In drosophila, the stem cells for sperm reside in a regulatory microenvironment called the hub.

TLS Online TPP Program

#Id: 3167

#Unit 11. Evolution and Behavior

Theory of recapitulation - Ernst Haeckel
He proposed that the embryonic development of an individual organism (its ontogeny) followed the same path as the evolutionary history of its species (its phylogeny).

TLS Online TPP Program

#Id: 4307

#Unit 11. Evolution and Behavior

Bergmann’s rule: populations in colder climates tend to have greater body mass than those

in warmer climates. This pattern is so common that it has a name.

TLS Online TPP Program

#Id: 4308

#Unit 11. Evolution and Behavior

Haldane’s rule: hybrid sterility or hybrid inviability is often limited to the heterogametic sex. (The heterogametic sex is the one with two different sex chromosomes, while the homogametic sex has two sex chromosomes of the same type).

TLS Online TPP Program

#Id: 4309

#Unit 11. Evolution and Behavior

Hamilton’s rule: It states that an allele that causes an altruistic behavior will spread if the following condition is met (rb>C)

TLS Online TPP Program

#Id: 4310

#Unit 11. Evolution and Behavior

Cope’s rule: A proposed generalization that individual body size in animals tends to increase during evolution.

TLS Online TPP Program

#Id: 4311

#Unit 11. Evolution and Behavior

Hitchhiking: Change in the frequency of an allele due to linkage with a selected allele at another locus.