Message 181 of 252 (816616) 08-08-2017 7:47 AM

Reply to: Message 180 by CRR 08-07-2017 9:28 PM

Fruitful discussion requires agreement on definitions. As a starting point, here's the definition of macroevolution from Wikipedia:

quote:

---

Macroevolution is evolution on a scale at or above the level of species, in contrast with microevolution, which refers to smaller evolutionary changes of allele frequencies within a species or population.
Macroevolution and microevolution describe fundamentally identical processes on different time scales.

---

In your view, what's wrong with that definition?

--Percy

Message 182 of 252 (816630) 08-08-2017 12:35 PM

Reply to: Message 180 by CRR 08-07-2017 9:28 PM

The explanation is gene loss in the chimp lineage, but not in the human lineage.

As you referenced in previous posts, there are human and hominoid specific genes that were not expressed in the common ancestor of all apes.

So you think the differences between humans and other apes is due solely to gene loss? None of those differences are due to the emergence of new genes or alterations to existing genes?

Do you consider the evolution of humans from a common ancestor shared with chimps to be macroevolution?

Ensembl is the one saying that there are orthologues of PLCXD1 in other primate genomes.

Message 183 of 252 (816660) 08-09-2017 3:52 AM

Reply to: Message 181 by Percy 08-08-2017 7:47 AM

[edit] Or from Message 107
microevolution = changes in gene frequencies and trait distributions that occur within populations and species
macroevolution = large evolutionary change, usually in morphology, typically refers to evolution of differences among populations that would warrant their plaecment in different genera or higher-level taxa

Edited by CRR, : [edit] Or from Message 107

Message 184 of 252 (816661) 08-09-2017 4:31 AM

Reply to: Message 182 by Taq 08-08-2017 12:35 PM

The Chimp genome has many genes that have, according to Ensemble, no homologue in the Human genome.
Is the explanation for this gene loss in the human lineage, but not in the chimp lineage?

Message 185 of 252 (816666) 08-09-2017 9:08 AM

Reply to: Message 183 by CRR 08-09-2017 3:52 AM

How can fruitful discussion about micro and macroevolution take place while disagreement about their definitions remains?

--Percy

Message 186 of 252 (816677) 08-09-2017 10:41 AM

Reply to: Message 184 by CRR 08-09-2017 4:31 AM

As already shown, there are homologues on the X chromosome for the genes lost on the Y chromosome. The differences between the chimp and human Y chromosomes are due to loss in the chimp genome. For other genes, the mechanism for new genes is gene duplication in either lineage and/or evolution of new transcription factors upstream of regions that were not previously transcribed. It is all in the papers in you have been referencing.

According to Ensembl there are parts of the human Y chromosome that are not present in the chimp Y chromosome, but are present in other ape Y chromosomes. Of the genes that are missing, there are homologues on the X chromosome. If Ensembl is what you trust, here is PLCXD1 mapped to the X chromosome at Ensembl:

http://www.ensembl.org/Homo_sapiens/Location/View?db=core...

Further down the X chromosome you can see SHOX, yet another of the genes on your list that has homologous sequence on the Y chromosome. See a pattern forming here? We can even see if there are homologues in the gorilla genome, and there are:

http://www.ensembl.org/Homo_sapiens/Location/Synteny?db=c...

Orangutan homologue? Yep, sure is:

http://www.ensembl.org/Homo_sapiens/Location/Synteny?g=EN...

This is not a human specific gene. The reason for the lack of a chimp homologue in the Y chromosome is gene loss as shown by the ape phylogeny.

Edited by Taq, : No reason given.

Edited by Taq, : No reason given.

Message 187 of 252 (816678) 08-09-2017 10:42 AM

Reply to: Message 183 by CRR 08-09-2017 3:52 AM

All apes, including humans, are in separate genera. Would you agree that humans evolving from a common ancestor shared with chimps would be an example of macroevolution?

Message 188 of 252 (816711) 08-09-2017 6:41 PM

Reply to: Message 186 by Taq 08-09-2017 10:41 AM

The Ensemble site also shows that chimps have many genes that have no homologue anywhere in the human genome. What do you think is the best explanation for this? Is it gene loss in the HUMAN lineage, but not in the CHIMP lineage?

We can look at orthologues later.

Message 189 of 252 (816713) 08-09-2017 7:27 PM

Reply to: Message 188 by CRR 08-09-2017 6:41 PM

Why wouldn't we expect something like a roughly equal amount of diversion between the species, assuming that they have a common ancestor?

Message 190 of 252 (816723) 08-10-2017 1:57 AM

Reply to: Message 189 by NoNukes 08-09-2017 7:27 PM

The Ensemble pages I linked previously show that humans have many genes that have no homologue anywhere in the chimp genome. Taq has stated that the best explanation is gene loss in the chimp lineage, but not in the human lineage, since separation from the common ancestor. Do you agree with Taq?

The Ensemble site shows that chimps have many genes that have no homologue anywhere in the human genome.
What do you think is the best explanation for this?

Message 191 of 252 (816738) 08-10-2017 10:42 AM

Reply to: Message 188 by CRR 08-09-2017 6:41 PM

I am focusing on the topic of the thread. That topic is a challenge given to ID/creationists to point to differences between the chimp and human genomes that could not be produced by known and observed mechanisms of mutagenesis. Gene loss is already a known and observed mechanism, so we can scratch that one off the list.

No RNA homologue or no DNA homologue? You need to be specific, and list the genes you are talking about. If it is limited to just the end of the chimp Y-chromosome, then the explanation has already been given which is gene loss in the chimp genome as evidenced by the presence of those genes in other ape genomes.

Message 192 of 252 (816739) 08-10-2017 10:44 AM

Reply to: Message 190 by CRR 08-10-2017 1:57 AM

I already showed you a reference dealing with those genes:

"The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor."
http://www.nature.com/...al/v463/n7280/full/nature08700.html

Are you saying that you disagree with this Nature paper?

Message 193 of 252 (816764) 08-10-2017 7:50 PM

Reply to: Message 192 by Taq 08-10-2017 10:44 AM

Are you counting this gene loss as microevolution or macroevolution?

Message 194 of 252 (816767) 08-10-2017 8:26 PM

Reply to: Message 193 by CRR 08-10-2017 7:50 PM

No, the best evolutionary explanationis that since separation, some genes have been lost and some new genes have been gained.

You have not shown that evolution only results in loss, so you cannot base your hypothesis on incomplete information.

Enjoy.

Message 195 of 252 (816769) 08-11-2017 12:49 AM

Reply to: Message 194 by RAZD 08-10-2017 8:26 PM

Are there genes that have been gained since separation? A list would be good if you can find one.
Would gene gain be counted as micro or macroevolution?