The Cambrian Explosion and Major Transitions

These flashcards cover key vocabulary terms and concepts from the lecture on the Cambrian explosion and major evolutionary transitions.

Cambrian Explosion

A major evolutionary event characterized by a rapid increase in the diversity and complexity of life forms.

Multicellularity

The state of being composed of multiple cells which can specialize for different functions.

Convergent evolution

The independent evolution of similar traits in different species due to adaptation to similar environments.

Coming Together Hypothesis

A hypothesis suggesting that multicellularity evolved when free-living, non-genetically related cells aggregated.

Staying Together Hypothesis

A hypothesis proposing that multicellularity occurred when genetically identical cells remained together after division.

Evolution of individuality

The development of individual organisms with the capacity to reproduce and pass on heritable traits.

Group-living

The behavior of living in groups that offers benefits such as better foraging and predator avoidance.

Disparity

The morphological differences and distinctness observed between species.

Diversity

The absolute number of species that resulted from an interplay of developmental systems in bilaterians.

Light Switch Theory

A theory proposing that the Cambrian explosion was driven by the emergence of new niches and predation challenges.

Abiotic environment

Non-living environmental factors, such as oxygen levels and climate, that influence biological evolution.

Negative C isotopic anomaly

An environmental change at the Neoproterozoic/Cambrian boundary associated with the extinction of Ediacaran fauna.

Hox genes

A group of related genes that control the body plan of an embryo along the head-tail axis.