How is comparative embryology used as evidence for evolution?

Embryology, the study of the development of the anatomy of an organism to its adult form, provides evidence for evolution as embryo formation in widely-divergent groups of organisms tends to be conserved. Another form of evidence of evolution is the convergence of form in organisms that share similar environments.

How are all developing embryos similar?

Embryology is a branch of comparative anatomy which studies the development of vertebrate animals before birth or hatching. Like adults, embryos show similarities which can support common ancestry. For example, all vertebrate embryos have gill slits and tails, as shown in Figure below.

What makes the developing vertebrate embryo similar after gastrulation?

All developing vertebrates appear very similar shortly after gastrulation. It is only later in development that the special features of class, order, and finally species emerge. All vertebrate embryos have gill arches, notochords, spinal cords, and primitive kidneys.

How do embryology similarities support evolution?

Embryos of organisms that have a closer genetic relationship to one another tend to look similar for a longer period of time since they share a more recent common ancestor. Thus, embryology is frequently used as evidence of the theory of evolution and the radiation of species from a common ancestor.

How do the similarities and differences between embryos provide evidence that evolution has occurred?

Evidence of an evolutionary common ancestor is seen in the similarity of embryos in markedly different species. Darwin used the science of embryology to support his conclusions. Embryos and the development of embryos of various species within a class are similar even if their adult forms look nothing alike.

How do embryos differ in structure?

Embryonic differentiation is the process of development during which embryonic cells specialize and diverse tissue structures arise. The differentiation of cells during embryogenesis is the key to cell, tissue, organ, and organism identity. Once an egg is fertilized by a sperm, a zygote is formed.

What causes the ovum to divide and go through differentiation during embryonic development?

Once an egg is fertilized by a sperm, a zygote is formed. The zygote divides into multiple cells in a process known as cleavage, triggering the beginning of embryonic differentiation. Cells in these three layers will give rise to different parts of the organism. The endoderm eventually becomes the gut.