How do scientist use similarities in embryology as evidence for evolution?

Answer 1

Although the recapitulation theory in its intact form is rejected by modern scientists, there is still some validity to Ernst Haeckel's theory in that the embryos look similar during early stages of development and in time differentiate into their respective species/kingdoms. This supports the common ancestry part of evolution.What is "the recapitulation theory"; it 'rings no bells' here.

Answer 2

Although the recapitulation theory in its intact form is rejected by modern scientists, there is still some validity to Ernst Haeckel's theory in that the embryos look similar during early stages of development and in time differentiate into their respective species/kingdoms. This supports the common ancestry part of evolution.

Answer 3

Like almost everything else in Biology, embryological development follows the pattern of nested hierarchies that we find throughout lifekind.

For instance, in all vertebrates the anus develops first - but not all of those organisms in which the anus develops first are vertebrates: vertebrates are a *subset* of deuterostomes.

This pattern of nested hierarchies persists all through biology, at all levels: it is found in individual genes and proteins, in morphological features, in behaviour, and in embryological development. And most of the features, whether genetic, behavioural, morphological or developmental, follow closely convergent patterns of nested hierarchies: whether one checks gene A or morphological feature B, one always arrives at a pattern in which apes are a subset of primates, and man is a subset of apes.

In this way, embryological development independently confirms the conclusion drawn from the other forms of these nested hierarchies.

Answer 4

When looking at embryos and all the stages they go through, you can see things develop that are not found on the newborn. In humans, we can see gills and even tails. The question, then is why. Looking at other animals as their embryos develop show similar patterns. The conclusion is that we have basically the same ancestors but we have branched off and are a separate species.