Tails tell us we've evolved

[rodeodance]

http://www.latimes.com/news/opinion/la-ed-tails15feb15,0,283979.story?coll=la-opinion-leftrail

Tails tell us we've evolved

Even though it seems humans born with tails would throw a kink in evolutionary theory, they're the exception that proves the rule.
February 15, 2007

HUMAN BABIES BORN with tails? That may sound like a headline from the Weekly World News, but it was the respected New Scientist magazine that recently published a cover story about the phenomenon of evolution "running backward." Entertainment value aside, the article represents a new twist in the politically charged debate about evolution.
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These and other throwbacks might seem to call into question the validity of evolution, which has been on something of a roll lately, with a federal judge's decision last year against a Pennsylvania school district that wanted to teach "intelligent design" and, only this week, the decision by the Kansas State Board of Education to repeal guidelines that said there was "considerable scientific and public controversy" over human origins.

In fact, Le Page suggests, atavisms like tails on humans are the exceptions that prove the evolutionary rule. Atavisms are possible, he says, because genes for primitive traits haven't disappeared from the genome; they simply have been switched off. In rare cases, they are switched back on (and then the tails are promptly snipped off). Sometimes, Le Page adds, so-called reverse evolution serves the cause of improving a species by allowing it to adapt to a changed environment.
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But the existence of atavism complicates the case against evolution. Far from undermining Darwinism, throwbacks challenge the creationist idea that every living species emerged full-blown in its present form. Atavism is impossible unless there's something to throw back to — like an ancestor with a tail that nobody wanted to snip off.

http://www.latimes.com/news/opinion/la-ed-tails15feb15,0,283979.story?coll=la-opinion-leftrail

[CrazyOrangeCat]

1. I've always been partial to tails . . .

(Very interesting article . . . thanks!)

[1620rock]

2. My eight cats have marvelous tails indeed.

[CrazyOrangeCat]

3. Wow! That's a handful!

I'm trying to keep it at four . . .

:hi:

[Henryman]

4. "Ontogeny recapitulates phylogeny".

I remember this from Comparable Vertebrae Anatomy in college.

Haeckel's theory

Ernst Haeckel's embryo drawings.Ontogeny is the growth (size change) and development (shape change) of an individual organism; phylogeny is the evolutionary history of a species. Haeckel's recapitulation theory claims that the development of the individual of every species fully repeats the evolutionary development of that species. Otherwise put, each successive stage in the development of an individual represents one of the adult forms that appeared in its evolutionary history. Haeckel formulated his theory as such: This notion later became simply known as recapitulation.

[CrazyOrangeCat]

5. That's quite an interesting theory.

Welcome to DU.

:thumbsup: