Chick and human early embryo comparison.?

Question

I was given 2 images of embryos which look very similar. One is a chick and the other is a human. It's not required to see them. Questions:
1. The embryos look very similar. Does this mean they have very similar DNA?
2. How could you test the above?
3. By altering the hormal/environmental conditions of either embryo, could you turn it into another kind of embryo?

First helpful answer gets 10 points..

Answer 1

1. not necessarily
2. genomic comparisons
3. no, you woul dhave to alter the Hox genes, but the embryo would still die anyway.

Answer 2

1) No
2) There are many ways to compare DNA. However, you can look at the end product and see how they compare.
3) No

Haeckel's theory of recapitulation, also called the biogenetic law or ontogeny recapitulates phylogeny is incorrect, at least in its strict form. There are, as pictures show, some similartity between embryos like humans and chickens, but the idea that ontogeny recapitulates phylogeny has been known to be wrong since early in the 20th century. While the strict form is wrong, there are some examples that show that organisms with an evolutionary history do show traits through the formation of the embryo.

There are some examples of this. From Wikipedia:

Generally, if a structure pre-dates another structure in evolutionary terms, then it also appears earlier than the other in the embryo. Species which have an evolutionary relationship typically share the early stages of embryonal development and differ in later stages. Examples include:

* The backbone, the common structure among all vertebrates such as fish, reptiles and mammals, appears as one of the earliest structures laid out in all vertebrate embryos.
* The cerebrum in humans, the most sophisticated part of the brain, develops last.

If a structure vanished in an evolutionary sequence, then one can often observe a corresponding structure appearing at one stage during embryonic development, only to disappear or become modified in a later stage. Examples include:

* Whales, which have evolved from land mammals, don't have legs, but tiny remnant leg bones lie buried deep in their bodies. During embryonal development, leg extremities first occur, then recede. Similarly, whale embryos (like all mammalian embryos) have hair at one stage, but lose most of it later.
* The common ancestor of humans and monkeys had a tail, and human embryos also have a tail at one point; it later recedes to form the coccyx.
* The swim bladder in fish presumably evolved from a sac connected to the gut, allowing the fish to gulp air. In most modern fish, this connection to the gut has disappeared. In the embryonal development of these fish, the swim bladder originates as an outpocketing of the gut, and is later disconnected from the gut."

If you are interested, the Wikipedia and Berkeley source below have a lot more information.

Answer 3

1. No
2. DNA testing
3. No.

Ontogeny recapitulates philogeny. This means the development of the individual follows the development of the species.

DNA is present from the earliest stages and includes the building blocks for the particular species. One cannot change the species of an embryo through environmental or hormonal differences.