Describe the four sources of evidence for evolution upon which Darwin based his ideas in common descent.

- Fossil record

- Geography

- Embryology

- Comparative anatomy

Explanation:

The four types of evidence for evolution upon which Darwin based his ideas were:

1-The geographic distribution of related species. The theory of evolution states that species evolve in geographic areas that were colonized by their ancestors.

2-The fossil record shows successions of organisms through time

3-Embryology: animal embryos in related species are very similar in the early stages of development but differentiate as they grow, thereby suggesting these species evolved from a common ancestor.

4-Comparative anatomy demonstrates physical and structural similarities between species. The species share anatomical similarities because they descend from a common ancestor (i.e., presence of homologies).

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.