Biogenetic Law": Ontogeny Recapitulates Phylogeny

JohnR7 · #1 16th July 2003, 09:43 PM

We first hear about The "biogenetic law" in the late 1800's by the German biologist Ernst Haeckel who suggests that humans have tails and gills during developmental stages.

It goes something like this: 1) Humans start off as a simple cell, as the first life was a cell. 2) They then go through a worm stage. 3) They develop gills and go though the fish stage. 4) They develop a tail and go through the amphibian stage. 5) Finally the gills and tail disappear and they become humans.

So what do you thing, does Haeckels theory of gills and the human tail suggest evolution?

Arikay · #2 16th July 2003, 09:50 PM

Well we dont go through stages, but some people do have non functioning gills and Tails.

This is good evidence though that gills or tails arent a freak thing, as they appear enough to have someone try and create a theory of why they appear.

Washington · #3 16th July 2003, 10:23 PM

The "law of recapitulation" has been discredited since the beginning of the twentieth century. Experimental morphologists and biologists have shown that there is not a one-to-one correspondence between phylogeny and ontogeny. Although a strong form of recapitulation is not correct, phylogeny and ontogeny are intertwined, and many biologists are beginning to both explore and understand the basis for this connection.

lucaspa · #4 16th July 2003, 10:27 PM

Originally Posted by JohnR7

We first hear about The "biogenetic law" in the late 1800's by the German biologist Ernst Haeckel who suggests that humans have tails and gills during developmental stages.

It goes something like this: 1) Humans start off as a simple cell, as the first life was a cell. 2) They then go through a worm stage. 3) They develop gills and go though the fish stage. 4) They develop a tail and go through the amphibian stage. 5) Finally the gills and tail disappear and they become humans.

So what do you thing, does Haeckels theory of gills and the human tail suggest evolution?

Here we go again. Misrepresentation of theories.

Darwin noted that development supported evolution because you could see SIMILARITIES with earlier forms.

Haeckel took this idea and pumped it full of steroids until he came up with the idea that the embryo goes thru the ADULT FORM of all its ancestors. Thus human embryos would go thru the adult forms of fish, amphibians, reptiles, and mammals.

Haeckel was wrong. The data falsified his idea at the time he proposed it and scientists said so. The Biogenic Law is a falsified theory.

However, Darwin's idea that related organisms go thru similar embryonic deveolopment is still valid and going strong.

http://zygote.swarthmore.edu/evo1.html

JohnR7 · #5 17th July 2003, 12:26 AM

Originally Posted by lucaspa

Haeckel was wrong. The data falsified his idea at the time he proposed it and scientists said so. The Biogenic Law is a falsified theory.

Then it has been falsifed that gill slits and the human tail bone is evidence for evolution?

JohnR7 · #6 17th July 2003, 12:29 AM

Originally Posted by lucaspa

Here we go again. Misrepresentation of theories.

How did I misrepresent Haeckel's theory?

Arikay · #7 17th July 2003, 12:43 AM

Falsifing a theory does Not falsify the evidence.

DrLao · #8 17th July 2003, 01:54 AM

Originally Posted by JohnR7

Then it has been falsifed that gill slits and the human tail bone is evidence for evolution?

No, they are evidence for evolution. And I suppose they do support Haeckle's biogenetic law. But that law is falsified in other ways. Most notably by the fact that human embryos are not fish, they are human. They have gill slits for a brief period, but never serve as functioning gills.

JohnR7 · #9 17th July 2003, 02:25 AM

Originally Posted by Arikay

Falsifing a theory does Not falsify the evidence.

Ok, so humans have tail bones. If you want to believe that is evidence for evolution then your free to believe what you want to believe. Just like I am free to believe that it is not evidence for evolution.

I just posted this topic so we could have a interesting conversation.

Jet Black · #10 17th July 2003, 03:45 AM

what are the tail bones for then? why did God put them there?
why have whales been discovered with complete legs, when no whales alive now have legs.... did god insert the code for legs in there just for a laugh?