Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 115 (8733 total)
Current session began: 
Page Loaded: 03-25-2017 9:28 AM
442 online now:
AZPaul3, Dr Adequate, jar, JonF, Percy (Admin), ThinAirDesigns, vimesey (7 members, 435 visitors)
Chatting now:  Chat room empty
Newest Member: timtak
Happy Birthday: OnlyCurious
Post Volume:
Total: 801,963 Year: 6,569/21,208 Month: 2,330/2,634 Week: 518/572 Day: 4/61 Hour: 1/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Prev1
...
89
10
11121314Next
Author Topic:   why is the lack of "fur" positive Progression for humans?
arrogantape
Member (Idle past 1990 days)
Posts: 87
Joined: 09-26-2008


Message 136 of 202 (508814)
05-16-2009 11:40 AM
Reply to: Message 135 by bluescat48
05-16-2009 1:19 AM


Re: A simple question ... dimorphism
RAZD, These are the points I am making

1) The notion we became upright by peering over long savannah grass has been discredited.

2) Another model is needed.

3) Generally we are not furry. We are the naked ape. Even the hairiest of us is no match for all the other apes coats.

4) It is a fact the barer we are, the faster we swim.

5) H Habilis migrated by water to far shores. So says the science community.

6) They have feet really only good for boost under and over water.

7) I think it is more than safe to assume H Habilis was the first naked ape. Why? because being smooth and sleek (don't forget our posterior) assists in efficient swimming. There is no valid argument chimp fur is fine for a swimmer. That is nonsense.

8) Certainly, the after Habilis path to H Sapiens would bring changes too.

Questions - Why do you think we are the naked ape? Why do we have smoothing subcutaneous fat? Why do we exude copious amount of salt through sweating? Why is fish a great food for our system, while red meat kills us?


This message is a reply to:
 Message 135 by bluescat48, posted 05-16-2009 1:19 AM bluescat48 has responded

Replies to this message:
 Message 137 by Theodoric, posted 05-16-2009 1:19 PM arrogantape has not yet responded
 Message 138 by RAZD, posted 05-16-2009 1:35 PM arrogantape has responded
 Message 139 by bluescat48, posted 05-16-2009 1:57 PM arrogantape has not yet responded

    
Theodoric
Member
Posts: 5700
From: Northwest, WI, USA
Joined: 08-15-2005
Member Rating: 2.9


Message 137 of 202 (508829)
05-16-2009 1:19 PM
Reply to: Message 136 by arrogantape
05-16-2009 11:40 AM


Re: A simple question ... dimorphism
1) The notion we became upright by peering over long savannah grass has been discredited.

I did not know this. Can you please point me to the literature.


Facts don't lie or have an agenda. Facts are just facts
This message is a reply to:
 Message 136 by arrogantape, posted 05-16-2009 11:40 AM arrogantape has not yet responded

    
RAZD
Member
Posts: 18241
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 138 of 202 (508833)
05-16-2009 1:35 PM
Reply to: Message 136 by arrogantape
05-16-2009 11:40 AM


Re: A simple question ... dimorphism
Still avoiding the dimorphism question, arrogantape,

1) The notion we became upright by peering over long savannah grass has been discredited.

It has been invalidated by evidence of upright gait before the savannah existed.

http://www.williamcalvin.com/teaching/bonobo.htm

quote:

Click to enlarge

Humans evolved from an ape species that existed about 6 million years ago (sometimes called "Pan prior"). About 2.5 million years ago, the common chimpanzee and the bonobo became separate lineages, as did bipedal woodland apes (e.g., Australopithecines) and our Homo lineage (in white). About 1 million years ago, both the gorilla and chimpanzee lineages split into east and west subspecies because of ice age droughts. Extinctions are shown by terminated bars; only arrows represent extant species.

2) Another model is needed.

Woodland dwelling bipedal apes fits the fossil evidence. Similar habitat and behavior are again seen in Bonobos

http://www.indymedia.ie/article/77573

quote:

Click to enlarge

3) Generally we are not furry. We are the naked ape. Even the hairiest of us is no match for all the other apes coats.

And this is where sexual dimorphism enters the picture, with male humans reaching the level of hair a chimp would have if they were as big as humans. On this thread (Sexual Selection, Stasis, Runaway Selection, Dimorphism, & Human Evolution) I have a broken link to a site with this information:

quote:
Let's look at this issue in a little more detail.

From Human Thermoregulation and Hair Loss (click)

Body hair is one of the most important features of the mammal thermoregulatory system. Hair can act as an important heat retention and heat prevention device in mammals. By trapping a layer of dead air against the skin, a layer of hair can act as an extremely efficient insulation, reducing the rate of convective heat loss to the environment. However, this exact same system acts as a way to prevent heat gain from the environment by the same principle; by using this layer of dead air to reduce the rate of convective heat gain from the environment to the skin. Besides insulation, the layer of hair on mammals is important in reducing the radiation from direct and indirect sunlight, and can thus act to reduce heat gain from the environment in two ways.

If loss of hair was an important variable in thermoregulation then we would expect {evolutionary pressure \ natural selection} to show a broad trend of hair thickness variations that could be correlated with the need to {retain\dissipate} heat.

We do see this. From the same source, here discussing the need of larger bodies to {retain less \ dissipate more} heat due to the increase in volume as the cube but skin area as the square of a size dimension:

The obvious solution to this situation is decreased body hair with increasing body size, which is exactly what is seen in anthropoids. When the number of hair follicles present in species per unit of area is compared with body size, all primates (including humans) fit along a regular log linear regression line, along which the density of hair per unit of area decreases as body size increases. Species like chimpanzees and gorillas have relatively fewer hair follicles per unit area of skin compared to the smaller monkeys. Humans fall along this line, and have a relative hair density almost the same as seen in chimpanzees, gorillas and orangutans.

To drive this point home, the number of hairs on the human body are precisely what they should be for the human body size. We are not displaced on the scale. There is no special loss of hair required for thermoregulation, and thus there is no special mechanism needed to provide for the loss of hair: no mutation is needed for the explanation of amount of human body hair.


Thus there is no loss of hair, humans have as many hair follicles per unit area as apes have when compared on a scale with body size. They do not deviate from the curve of the other apes. The number of hair follicles is normal for an ape of our size.

What we have is the arrested development of hair from childhood patterns to adult patterns, a change that occurs with becoming capable of reproduction. Such arrested development is common in species where they evolve to be capable of reproduction before becoming fully developed.

4) It is a fact the barer we are, the faster we swim.

It is a fact that every furred marine mammal can swim faster than humans, from sea otters to harbor seals to elephant seals. Thus the fact is that we are NOT adapted to swim, unlike otters and seals. Their adaptations to swimming have nothing to do with furriness, and thus furriness on it's own is neither here nor there when it comes to swimming ability.

It is a fact that shaving off all hair makes humans faster swimmers, thus adaptation for swimming would remove all hair equally - no sexual dimorphism, no long tangled curly head hair, no hair at all.

The fact that you cannot explain the sexual dimorphism of humans with swimming means that it is a falsified conjecture. A valid hypothesis explains ALL the known evidence and is NOT contradicted by any known evidence. The bi-pedal forest dwelling ape with sexual selection explains the evidence of gait, of sexual dimorphism, and it matches the distribution of all fossils, not just those alone shores.

5) H Habilis migrated by water to far shores. So says the science community.

And also inland, away from the shores. We also see Polynesian people no more adapted to a water swimming life-style than Tibetans. What you are employing is the post hoc ergo propter hoc fallacy coupled with ignoring the evidence of H.habilis living inland, and in virtually complete denial about sexual dimporphism.

There is no valid argument chimp fur is fine for a swimmer. That is nonsense.

Which is the argument from incredulity, plus completely ignoring the swimming ability of otters and seals.

All you are doing is cherry picking evidence to suit your conjecture and reveling in Confirmation Bias:

Confirmation Bias (Wikipedia, 2009)
In psychology and cognitive science, confirmation bias is a tendency to search for or interpret new information in a way that confirms one's preconceptions and avoids information and interpretations which contradict prior beliefs. It is a type of cognitive bias and represents an error of inductive inference, or as a form of selection bias toward confirmation of the hypothesis under study or disconfirmation of an alternative hypothesis.

Confirmation bias is of interest in the teaching of critical thinking, as the skill is misused if rigorous critical scrutiny is applied only to evidence challenging a preconceived idea but not to evidence supporting it.[1]

So once again, I point out that your continued ignoring of the evidence of sexual dimorphism shows that your conjecture is false. From Message 133

quote:
Message 126
So how do you explain the dimorphism in hair patterns between males and females in humans and the lack of sexual dimorphism in hair patterns between males and females in marine mammals from heavily furred seals to bare whales.

If you cannot explain the dimporphism, then your conjecture cannot explain the apparent hairlessness of humans, no matter what your conjecture involves.

In other words, your conjecture is dead in the water.


Your inability to address the issue of sexual dimorphism is evidence of Cognitive Dissonance

Cognitive dissonance (Wikipedia, 2009)
Cognitive dissonance is an uncomfortable feeling caused by holding two contradictory ideas simultaneously. The "ideas" or "cognitions" in question may include attitudes and beliefs, and also the awareness of one's behavior. The theory of cognitive dissonance proposes that people have a motivational drive to reduce dissonance by changing their attitudes, beliefs, and behaviors, or by justifying or rationalizing their attitudes, beliefs, and behaviors.[1] Cognitive dissonance theory is one of the most influential and extensively studied theories in social psychology.

A powerful cause of dissonance is when an idea conflicts with a fundamental element of the self-concept, such as "I am a good person" or "I made the right decision." This can lead to rationalization when a person is presented with evidence of a bad choice. It can also lead to confirmation bias, the denial of disconfirming evidence, and other ego defense mechanisms.

You cannot explain the sexual dimorphism, so you don't even talk about the issue. This is denial of the reality that sexual dimorphism is more of the issue than the actual amount of hair on humans. Male humans have hair that varies from ape-like to female like, while females have predominantly arrested juvenile hair patterns of vellus hair.

If adaptation to swimming were happening that the hunter should be the fastest and most powerful swimmer, and as a result should also be the sex with the least visible hair. This is exactly opposite of the evidence.

Let me repeat: it is exactly the opposite of the evidence. Thus the conjecture is invalid.

8) Certainly, the after Habilis path to H Sapiens would bring changes too.

Which is just saying that evolution will occur, not that there will necessarily be adaptation for or against aquatic ability. This is known as a non-sequitur fallacy.

Why do we have smoothing subcutaneous fat?

For thermoregulation. Why do we have sweat glands? Whales don't. Seals don't. Do you realize that every piece of evidence that you have cherry-picked is countered by pieces of evidence that you have ignored?

Confirmation Bias
Cognitive Dissonance
Denial

If you cannot explain the dimporphism, then your conjecture cannot explain the apparent hairlessness of humans, no matter what your conjecture involves.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 136 by arrogantape, posted 05-16-2009 11:40 AM arrogantape has responded

Replies to this message:
 Message 140 by arrogantape, posted 05-16-2009 5:35 PM RAZD has responded

  
bluescat48
Member (Idle past 1539 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 139 of 202 (508837)
05-16-2009 1:57 PM
Reply to: Message 136 by arrogantape
05-16-2009 11:40 AM


Re: A simple question ... dimorphism
quote:
H Habilis migrated by water to far shores. So says the science community.

Where does it say by swimming? Ever heard of a raft?


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


This message is a reply to:
 Message 136 by arrogantape, posted 05-16-2009 11:40 AM arrogantape has not yet responded

    
arrogantape
Member (Idle past 1990 days)
Posts: 87
Joined: 09-26-2008


Message 140 of 202 (508847)
05-16-2009 5:35 PM
Reply to: Message 138 by RAZD
05-16-2009 1:35 PM


Re: A simple question ... dimorphism
Dimorphism. You trot this trait out and call it a deal breaker. I happen to have pigmented hair all over my body. It grows, stretched out, to about a centimeter. Male gorillas are a whole lot bigger than me, and though different tribes vary in fur covering, they both have far more fur than you and I. I guess gorillas are some kind of exception.

The Hobbit was a hominid remnant on an island with no large carnivores. I doubt very much these flat footed hominids crossed India on foot. Their feet would be a big hindrance. The literature says they moved by water. I will go with that. H Habilis was handy, but weaving sea going rafts is going to have to wait for the polynesians. For such a small animal, flight would be the best defense. Running is not an option. Jumping into and diving under the water is a very good defense against land carnivores.

My little hairs hold me back little, compared to any clothing. When I pull myself out of the river onto a sunny rock, I can feel my hairs, as they spring outward after a quick dry.

When one is suffering from wet hypothermia the field procedure to follow is to strip the sufferer from his wet clothes, and and sandwich him between two naked bodies under down covers. The point being, clothing and fur are good for some things, but not for swimming. Matted fur would take exponentially longer to dry than our puny hairs.

H Habilis would be no more inclined to migrate over the world than a chimp, if it didn't have some advantageous development. The long flat foot makes a great flipper. If he is going to have a specialized feet, then it is easy to imagine smooth lightly haired bodies too.

You also like to compare our bodies to seals and the such. Cormorants dive into the water to catch fish. So do penguins. Cormorants have to dry themselves, unfolding their wings to air dry, or warm themselves. Penguins are more specialized doing the same thing. The White Tailed Kite can hover, and uses this capability to catch prey. However, the White Tailed Kite is no hummingbird.

Seals, if they could stand, would be bipedal, their hind quarters in line. We humans are extremely graceful with the water. No other ape can even approach our ability in water. We use our talent to spear fish, and gather abalone.


This message is a reply to:
 Message 138 by RAZD, posted 05-16-2009 1:35 PM RAZD has responded

Replies to this message:
 Message 141 by bluescat48, posted 05-16-2009 5:41 PM arrogantape has responded
 Message 143 by RAZD, posted 05-16-2009 10:21 PM arrogantape has not yet responded

    
bluescat48
Member (Idle past 1539 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 141 of 202 (508849)
05-16-2009 5:41 PM
Reply to: Message 140 by arrogantape
05-16-2009 5:35 PM


Re: A simple question ... dimorphism
arrogantape writes:

Jumping into and diving under the water is a very good defense against land carnivores.

Yeah, providing the water is not infested with crocs & sharks.

arrogantape writes:

but weaving sea going rafts is going to have to wait for the polynesians.

So are you saying that they swam from Africa to Borneo?

Edited by bluescat48, : Added 2d comment


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


This message is a reply to:
 Message 140 by arrogantape, posted 05-16-2009 5:35 PM arrogantape has responded

Replies to this message:
 Message 142 by arrogantape, posted 05-16-2009 6:24 PM bluescat48 has responded

    
arrogantape
Member (Idle past 1990 days)
Posts: 87
Joined: 09-26-2008


Message 142 of 202 (508852)
05-16-2009 6:24 PM
Reply to: Message 141 by bluescat48
05-16-2009 5:41 PM


Re: A simple question ... dimorphism
Hi Bluesat48, The move of H Habilis to Flores was a migratory move. This is easy to a handle on if your foodstuff exists in a narrow band along the coast. It's like us trout fishermen. Out of courtesy, we circumvent a hole being fished by another, and move onto the next.

I answered your boat question, but it was buried. Handy Man was surely keen for a little brain fellow. but he was no captain.

Oh yeah, sharks and crocs. No one said Handy Man had a free ride. H Erectus took the land route to the same environs in Indonesia. He had legs, feet, and height we have,

Edited by arrogantape, : No reason given.


This message is a reply to:
 Message 141 by bluescat48, posted 05-16-2009 5:41 PM bluescat48 has responded

Replies to this message:
 Message 144 by bluescat48, posted 05-17-2009 1:45 AM arrogantape has responded

    
RAZD
Member
Posts: 18241
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 143 of 202 (508871)
05-16-2009 10:21 PM
Reply to: Message 140 by arrogantape
05-16-2009 5:35 PM


Re: A simple question ... dimorphism
Let me explain in greater detail, arrogantape, why dimorphism is a problem for you.

I happen to have pigmented hair all over my body. It grows, stretched out, to about a centimeter.

And I get 1-1/2" on my arms and longer on my legs, and there are men with a LOT more, but this is not sexual dimorphism.

http://en.wikipedia.org/wiki/Sexual_dimorphism

quote:
Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. Examples include color (specifically referred to as sexual dichromatism), size, and the presence or absence of parts of the body used in courtship displays or fights, such as ornamental feathers, horns, antlers or tusks.

Click to enlarge

Female (left) and male Common Pheasant, illustrating the dramatic difference in both color and size between sexes.

The question is, why does the female hair pattern differ so markedly from the male pattern IF selection is for less hair in general?

If selection was for less hair in general, then the selection would act on the species independent of sex, and both would have the same amount of less visible hairs.

When one is suffering from wet hypothermia ...

... it just proves that humans are NOT adapted to an aquatic lifestyle. Seals in the arctic don't get hyperthermia, nor do furless whales.

You are still engaged in cherry picking your evidence with confirmation bias, and ignoring the real problem for you conjecture:

Why is there a difference in the hair patterns of men and women? Why are women universally endowed with the arrested velus hair pattern? Why do males vary from hair similar women and hair similar to other apes?

Why is there little variation in women? Why is the mean value for women all the way to one end of the available spectrum for hair development?

Why is there a lot of variation in men? Why is the mean value for men in the middle of the available spectrum for hair development?

Why is it, that the apparent hairlessness of women needs to be enhanced even further by artificial means, and why is it done for mating and not for swimming?

Please explain each of these questions with aquatic adaptation.

Enjoy.

Edited by RAZD, : ]


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 140 by arrogantape, posted 05-16-2009 5:35 PM arrogantape has not yet responded

  
bluescat48
Member (Idle past 1539 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 144 of 202 (508880)
05-17-2009 1:45 AM
Reply to: Message 142 by arrogantape
05-16-2009 6:24 PM


Re: A simple question ... dimorphism
arrogantape writes:

Handy Man was surely keen for a little brain fellow. but he was no captain.

Now one last question, where is the evidence that habilis ever left Africa.

William R. Leonard Food for Thought, Dec 2002 writes:

The evolution of H. erectus in Africa 1.8 million yeares ago also marked the third turning point in human evolution: the initial movement of hominids out of Africa. Until recently, the locations and ages of known fossil sites suggested that early homo stayed put for a few hundred thousand years before venturing out of the motherland ans slowly fanning out into the rest of the Old World. Earlier work hinted that improvements in tool technology around 1.4 million years ago--namely, the advent of the Acheulean hand ax--allowed homimids to leave Africa. But new discoveries indicate that H. erectus hit the ground running, so to speak. Rutgers University geochronologist Carl Swisher III and his colleages have shown that the earliest H. erectus sites outside of Africa, which are in Indonesia and the Republic of Georgia, date to between 1.8 million and 1.7 million years ago.

nowhere does it state that h. habilis ever left Africa. A map inclued with the article shows the route taken by H. erectus
but shows that H habilis stayed in the area between Olduvai Gorge and Lake Turkana.


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


This message is a reply to:
 Message 142 by arrogantape, posted 05-16-2009 6:24 PM arrogantape has responded

Replies to this message:
 Message 145 by arrogantape, posted 05-17-2009 12:02 PM bluescat48 has not yet responded

    
arrogantape
Member (Idle past 1990 days)
Posts: 87
Joined: 09-26-2008


Message 145 of 202 (508942)
05-17-2009 12:02 PM
Reply to: Message 144 by bluescat48
05-17-2009 1:45 AM


Re: A simple question ... dimorphism
""""nowhere does it state that h. habilis ever left Africa. A map inclued with the article shows the route taken by H. erectus
but shows that H habilis stayed in the area between Olduvai Gorge and Lake Turkana.""""

Except for one thing. H Florensis is very much the same as H Habilis. Comparing skulls, the similarity is striking.

H Erectus had a body like ours, with a not ready brain. H Florensis is very unlikely to have evolved from H Erectus because of H Florensis's decididly archaic rists and feet.


This message is a reply to:
 Message 144 by bluescat48, posted 05-17-2009 1:45 AM bluescat48 has not yet responded

Replies to this message:
 Message 146 by RAZD, posted 05-17-2009 3:51 PM arrogantape has responded

    
RAZD
Member
Posts: 18241
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 146 of 202 (508960)
05-17-2009 3:51 PM
Reply to: Message 145 by arrogantape
05-17-2009 12:02 PM


Re: A simple question ... dimorphism
Hi again arrogantape

""""nowhere does it state that h. habilis ever left Africa. A map inclued with the article shows the route taken by H. erectus
but shows that H habilis stayed in the area between Olduvai Gorge and Lake Turkana.""""

type [qs]quotes are easy[/qs] and it becomes:

quotes are easy

or type [quote]quotes are easy[/quote] and it becomes:

quote:
quotes are easy

also check out (help) links on any formating questions when in the reply window.

Except for one thing. H Florensis is very much the same as H Habilis. Comparing skulls, the similarity is striking.

How about when you factor in skeletal height? What is remarkable about H.floresiensis is the small overall size as well as the small braincase

http://en.wikipedia.org/wiki/Homo_floresiensis

quote:
In addition to a small body size, H. floresiensis had a remarkably small brain. The type specimen, at 380 cm (23 in), is at the lower range of chimpanzees or the extinct australopithecines.[1][5] The brain is reduced considerably relative to this species' presumed immediate ancestor H. erectus, which at 980 cm (60 in) had more than double the brain volume of its alleged descendant species.[5] Nonetheless, the estimated brain to body mass ratio of LB1 lies between that of H. erectus and the great apes.[19]
...
Recent research of Lyras et al.,[15] based on 3D-morphometrics, shows that the skull of LB1 differs significantly from all H. sapiens skulls, including those of small-bodied individuals and microcephalics, and is similar only to the skull of Homo erectus.

Brain size alone is not indicative of relationship, rather it is the overall pattern that is consistent with H. erectus rather than H. habilis.

Compare the shape of the skull between these pictures:



Click to enlarge
H. habilis

Click to enlarge
H. erectus

Click to enlarge
H. floresiensis

Or you can compare the middle picture above to the lineage shown here:
http://www.talkorigins.org/faqs/comdesc/hominids.html
quote:

Click to enlarge

Figure 1.4.4. Fossil hominid skulls. Some of the figures have been modified for ease of comparison (only left-right mirroring or removal of a jawbone). (Images 2000 Smithsonian Institution.)
(A) Pan troglodytes, chimpanzee, modern
(B) Australopithecus africanus, STS 5, 2.6 My
(C) Australopithecus africanus, STS 71, 2.5 My
(D) Homo habilis, KNM-ER 1813, 1.9 My
(E) Homo habilis, OH24, 1.8 My
(F) Homo rudolfensis, KNM-ER 1470, 1.8 My
(G) Homo erectus, Dmanisi cranium D2700, 1.75 My
(H) Homo ergaster (early H. erectus), KNM-ER 3733, 1.75 My
(I) Homo heidelbergensis, "Rhodesia man," 300,000 - 125,000 y
(J) Homo sapiens neanderthalensis, La Ferrassie 1, 70,000 y
(K) Homo sapiens neanderthalensis, La Chappelle-aux-Saints, 60,000 y
(L) Homo sapiens neanderthalensis, Le Moustier, 45,000 y
(M) Homo sapiens sapiens, Cro-Magnon I, 30,000 y
(N) Homo sapiens sapiens, modern

Does H. floresiensis match better to (D), (E), (F), (G) or some other skull? If I had to pick on skull alone and only using these pictures, I would pick (G), based on the flat face, the brow ridges and the relative size of the braincase to the face. Curiously this is from the site of the first evidence of of erectus outside africa:

http://www.dmanisi.org.ge/index.html: First Europeans
http://www.nature.com/nature/journal/v449/n7160/full/nature06134.html

quote:
The Plio-Pleistocene site of Dmanisi, Georgia, has yielded a rich fossil and archaeological record documenting an early presence of the genus Homo outside Africa. Although the craniomandibular morphology of early Homo is well known as a result of finds from Dmanisi and African localities, data about its postcranial morphology are still relatively scarce. Here we describe newly excavated postcranial material from Dmanisi comprising a partial skeleton of an adolescent individual, associated with skull D2700/D2735, and the remains from three adult individuals. This material shows that the postcranial anatomy of the Dmanisi hominins has a surprising mosaic of primitive and derived features. The primitive features include a small body size, a low encephalization quotient and absence of humeral torsion; the derived features include modern-human-like body proportions and lower limb morphology indicative of the capability for long-distance travel. Thus, the earliest known hominins to have lived outside of Africa in the temperate zones of Eurasia did not yet display the full set of derived skeletal features.

Have you considered how those morphological (ie body shape) features match those of H. floresiensis?

Wiki again:

quote:
William L. Jungers of the Stony Brook University in New York compared the low twist of the arm bone of H. floresiensis to the similarly small humeral torsion of an early hominid from Dmanisi in Georgia,[46] usually designated as Homo georgicus. ...

Note: the Dmanisi find is on a hilltop, not a coastline.

Enjoy.

PS - scientific nomenclature capitalizes the genus and lowercases the species, thus H. erectus is correct and H. Erectus is not.

In addition, H. floresiensis is named after the island where they were found: "It was named after the Indonesian island of Flores on which the remains were found" ... so the name is floresiensis.

Just some nitpicks to improve your posting


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 145 by arrogantape, posted 05-17-2009 12:02 PM arrogantape has responded

Replies to this message:
 Message 147 by arrogantape, posted 05-17-2009 8:40 PM RAZD has responded

  
arrogantape
Member (Idle past 1990 days)
Posts: 87
Joined: 09-26-2008


Message 147 of 202 (508988)
05-17-2009 8:40 PM
Reply to: Message 146 by RAZD
05-17-2009 3:51 PM


Re: A simple question ... dimorphism
RAZD, Thanks for the quote tutoring. I am a grab the package and rip male. Also, thanks for the pretty pictures of hominid skulls. you are not showing me anything I don't know, however.

I am sure you understand the path to Homo Sapiens is unsure. The fact Habilis is thought to have given rise to H Heidelbergensis, H Georgicus, and perhaps H Erectus, it's my opinion there is no reason to think we are descendants of H Erectus as well.

H Habilis, despite it's small brain, was quite handy. Interesting H Georgicus individuals were found way up in the old USSR. I instantly got this vision of these guys looking out upon the steppes, and muttering, "We ain't in Africa anymore," just before their demise. These archaic heroes fit Japanese movie scripts of the unsung warrior very well.

You have to wonder what these guys were doing there, and why they are lonely in the fossil record. They are thought derivative from H Habilis, as is most likely H Florensius. I don't think H Erectus ever played a part in our evolution. H Habilis, if H Florensis is their kin. was long lived and successful.

Unfortunately, we don't have feet fossils. That would clear up a lot of questions. I found I am not alone in thinking H Habilis started the nudist trait. I got this from Wikipedia:

[Such traits as noticeable whites in the eyes, smaller hairs resulting in exposed skin, and a naked appearance remain theoretical.]

Yes, theoretical. That is all we have. Like you, I am a vigilant student of physical anthropology.


This message is a reply to:
 Message 146 by RAZD, posted 05-17-2009 3:51 PM RAZD has responded

Replies to this message:
 Message 148 by RAZD, posted 05-17-2009 10:28 PM arrogantape has responded

    
RAZD
Member
Posts: 18241
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.0


Message 148 of 202 (508999)
05-17-2009 10:28 PM
Reply to: Message 147 by arrogantape
05-17-2009 8:40 PM


woodland forest apes and bareness selection
Excellent arrogantape,

H Habilis, despite it's small brain, was quite handy. Interesting H Georgicus individuals were found way up in the old USSR. I instantly got this vision of these guys looking out upon the steppes, and muttering, "We ain't in Africa anymore," just before their demise. These archaic heroes fit Japanese movie scripts of the unsung warrior very well.

Yes, what I have seen is that human intelligence has increased by two methods: an increase in sheer brain volume, and an increase in the rippling of the brain surface. Both of these increase surface area, and studies show that it is surface area that is critical to intelligence - it's where the thoughts occur. Thus a small size brain in today's population is not mentally handicapped, while a person with a smooth surface brain is - our brains are incredibly rippled.

You have to wonder what these guys were doing there, and why they are lonely in the fossil record. They are thought derivative from H Habilis, as is most likely H Florensius. I don't think H Erectus ever played a part in our evolution. H Habilis, if H Florensis is their kin. was long lived and successful.

I sometimes wonder if less fit hominid populations were driven from the homeland by more dominant (new?) populations, and then stumbled on the rest of the world. The new species drive the old species away. This would explain the primitive features in the Dmanisi and Flores Island skeletons.

I agree with you on H.erectus and H.saps being cousin species at best. I also think that H.erectus preceeded H.saps out of africa, and were later over-run by the H.saps in much the same way that we are cousin species to H.neander and over-ran them. I've seen mention of this in the literature.

With that scenario though, it is also reasonable to me that H.floresiensis could descend from H.erectus and also be a cousin species.

Unfortunately, we don't have feet fossils. That would clear up a lot of questions. I found I am not alone in thinking H Habilis started the nudist trait. I got this from Wikipedia:

(Such traits as noticeable whites in the eyes, smaller hairs resulting in exposed skin, and a naked appearance remain theoretical.)

I'll go out on a limb: I strongly believe the naked appearance evolved in the woodland forest environment back at the beginning of the divide from chimpanzees. See Message 65 and the issue of enabling mechanisms.

quote:
Given this environment, substantial {apparent bareness} could develop without jeopardizing survival through overheating. This would indicate that the primary concern in this environment would be to prevent heat loss rather than getting too hot, at least during the initial stages.

A cool shaded environment enables the development of bareness while only having to provide alternate heat retention mechanisms, and not have to provide both retention and dissipation.


Our cardiovascular system is able to cope with a significant range of temperatures by regulating the flow of blood to the skin surface or shutting it down, so this would enable sexual selection of apparent bareness to occur without threatening survival of the species. Such selection would also be sufficient to divide human populations from chimpanzee populations.

quote:
One advantage of the vascular system is that it works for both heat retention and cooling, thus it is best able to replace both those functions lost with hair reduction, especially for daily fluctuations where a fairly rapid response would be needed. The disadvantage is that it is not as capable of modulating extremes of heat and cold as hair would be.

Another heat retention system common to many mammals is a thicker layer of subcutaneous fat. This layer exists in all primates, but is most developed in humans. ...

...

If anyone doubts the ability of these mechanisms to provide sufficient protection from hypothermia (not too cold), then consider that when the Beagle reached the area of Tiera del Fuego at the south end of South America, that the crew were welcomed by nearly naked natives while Darwin and the others froze with the clothes they had on:

From http://geography.about.com/library/misc/uctierra.htm

On one occasion Darwin and crew were near a good size fire and still quite cold, while the aborigines were some distance away and perspiring heavily. Charles noted this with great interest.

(same broken link on thermoregulation, unfortunately).

Thus the increased subcutaneous fat in humans enabled survival in colder environments OR it allowed the further reduction of hair development by sexual selection.

Thus I can posit sexual selection as the driving force for apparent bareness, enabled initially in the wooded forest environment by the lack of extreme temperatures year round, and then enabled by selection for increased subcutaneous fat as the bareness increased in area. This gives us "naked" bipedal apes pre-adapted to move into the savannah, where the sweat mechanism was further developed from the already existing Eccrine glands - glands that show up in similar distributions in chimps and gorillas, but not in other apes, suggesting this distribution occurred before the human\chimp\gorilla split. See Message 70.

Interestingly, the initial purpose of eccrine glands is to keep bare skin supple and soft, so the existence of these glands on chest areas of humans\chimps\gorillas would indicate an ancestor with a bare chest. Note that there is also matching evidence of bareness in gorilla males and in lactating females chimps and gorillas, so it may be that selection for some bareness patterns occurred even earlier than I have posited.

This, of course, makes the aquatic ape conjecture unnecessary, even if it were capable of generating sexually dimorphic hair distributions ... (which I'm still waiting to see some explanation of)

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 147 by arrogantape, posted 05-17-2009 8:40 PM arrogantape has responded

Replies to this message:
 Message 149 by arrogantape, posted 05-18-2009 11:32 AM RAZD has responded

  
arrogantape
Member (Idle past 1990 days)
Posts: 87
Joined: 09-26-2008


Message 149 of 202 (509068)
05-18-2009 11:32 AM
Reply to: Message 148 by RAZD
05-17-2009 10:28 PM


Re: woodland forest apes and bareness selection
RAZD, we are agreeing on more things, showing flexibility, for one thing, and perhaps we are not so different in our opinions overall.

I am going to have to work on the procedures to upload photos, and outside quotes. There is a picture I found of Floriensis's foot compared to it's femur. You probably have seen it. The foot is monstrous. It is not only long, it is wide as well and totally flat. That is a ridiculous adaptation for land use. The only thing I can think of where their foot can be an asset is for underwater swimming. Being a former scuba diver, I can attest to the serious gain in propulsion using a flat, wide, and long flipper.

Well, off to another science forum where folks are arguing birds aren't dinosaurs.


This message is a reply to:
 Message 148 by RAZD, posted 05-17-2009 10:28 PM RAZD has responded

Replies to this message:
 Message 150 by bluescat48, posted 05-18-2009 1:46 PM arrogantape has responded
 Message 154 by RAZD, posted 05-20-2009 10:25 PM arrogantape has responded

    
bluescat48
Member (Idle past 1539 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 150 of 202 (509084)
05-18-2009 1:46 PM
Reply to: Message 149 by arrogantape
05-18-2009 11:32 AM


Re: woodland forest apes and bareness selection
arrogantape writes:

It is not only long, it is wide as well and totally flat. That is a ridiculous adaptation for land use.

Funny Bears get along on land fine on Wide flat feet so do humans with bilateral pes platus (flat feet).


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


This message is a reply to:
 Message 149 by arrogantape, posted 05-18-2009 11:32 AM arrogantape has responded

Replies to this message:
 Message 151 by arrogantape, posted 05-18-2009 4:01 PM bluescat48 has responded

    
Prev1
...
89
10
11121314Next
Newer Topic | Older Topic
Jump to:


Copyright 2001-2015 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2017