Embryo drawing

related topics
{theory, work, human}
{specie, animal, plant}
{work, book, publish}
{@card@, make, design}
{film, series, show}
{law, state, case}
{woman, child, man}

Embryo drawing refers to any representation of the illustration of embryos in their developmental sequence. In plants and animals, an embryo develops from a zygote, the single cell that results when an egg and sperm fuse during fertilization. In animals, the zygote divides repeatedly to form a ball of cells, which then forms a set of tissue layers that migrate and fold to form an early embryo. Images of embryos provide a means of comparing embryos of different ages, and species. To this day, embryo drawings are made in biology undergraduate developmental biology lessons.

Comparing different embryonic stages of different animals is a tool that can be used to infer relationships between species, and thus biological evolution. This has been a source of quite some controversy, both now as in the past. A biologist who pioneered in this field was Ernst Haeckel. By comparing different embryonic stages of different vertebrate species, he formulated the Recapitulation theory. This theory states that an animal's embryonic development follows exactly the same sequence as the sequence of its evolutionary ancestors. Haeckel's work and the ensuing controversy linked the fields of developmental biology and comparative anatomy into comparative embryology. From a more modern perspective, Haeckel's drawings were the beginnings of the field of evolutionary developmental biology (evo-devo).

The study of comparative embryology aims to prove or disprove that vertebrate embryos of different classes (e.g. mammals vs. fish) follow a similar developmental path due to their common ancestry. Such developing vertebrates have similar genes, which determine the basic body plan. However, further development allows for the distinguishing of distinct characteristics as adults.

Contents

Full article ▸

related documents
Nature
Nature versus nurture
Stephen Jay Gould
Sexual selection
Sociobiology
Punctuated equilibrium
Postmodern philosophy
Northrop Frye
The nature of God in Western theology
Philosophical Investigations
Jürgen Habermas
Wikipedia:Neutral point of view/Examples Debate
Evolutionary psychology
Socratic method
Metaphilosophy
Imre Lakatos
Lev Vygotsky
Learning theory (education)
Conceptual metaphor
Emergence
Technological singularity
Memetics
Thomas Henry Huxley
Pantheism
Cultural studies
Internalism and externalism
Where Mathematics Comes From
Judith Butler
Social Darwinism
Noble Eightfold Path