BIOL300 Ecology/Evolution Study Guide, Exam 1

These flashcards cover key concepts, events, and mechanisms important for understanding ecology and evolution as outlined in the lecture notes.

What are the three main species concepts discussed in the lecture?

Biological Species Concept, Phylogenetic Species Concept, Lineage Species Concept.

What is the key distinction between allopatric speciation and sympatric speciation?

Allopatric speciation occurs due to geographic isolation, while sympatric speciation occurs without geographic barriers.

What is reinforcement in the context of speciation?

Reinforcement refers to the process where natural selection increases reproductive isolation between hybridizing species.

List the five major types of prezygotic isolating mechanisms.

Geographic isolation, Habitat isolation, Behavioral isolation, Temporal isolation, Mechanical isolation.

What was significant about the Ediacaran Period?

It is noted for early multicellular life and key events leading to the Cambrian Explosion.

What is the oxygen catastrophe, and what caused it?

It was an event during the Precambrian when oxygen levels increased dramatically, likely due to photosynthesis, drastically changing life and evolution.

Describe the role of gametic isolation in prezygotic isolation mechanisms.

Gametic isolation occurs when sperm and egg from different species cannot fuse to form a zygote.

What are the potential benefits of sexual reproduction compared to asexual reproduction?

Increased genetic diversity, allowing for better adaptation to changing environments.

What was the significance of the Burgess Shale?

It is renowned for its exceptional fossil preservation, providing insight into early marine life during the Cambrian Explosion.

What is the concept of polyploidy in speciation?

Polyploidy is a condition arising from the duplication of whole sets of chromosomes, often leading to speciation, especially in plants.

Explain the concept of adaptive radiation.

Adaptive radiation is the rapid evolution of diversely adapted species from a common ancestor in response to new environments.

What are the three types of postzygotic isolating mechanisms?

Reduced hybrid viability, Reduced hybrid fertility, Hybrid breakdown.

What are synapomorphies, and why are they important in taxonomy?

Synapomorphies are shared derived traits that indicate common ancestry, helping to classify organisms into groups.

How do geological events like Pangaea influence evolution?

The formation and breakup of continents can lead to isolation or connectivity of populations, driving speciation and diversification.

Why is RNA considered important for the origin of living things?

RNA is hypothesized to have played a crucial role in early life due to its ability to store genetic information and catalyze reactions.

What were five general characteristics of the Precambrian that made it hostile to life?

High radiation levels, extreme temperatures, unstable environments, lack of oxygen, and harsh chemical conditions.

During which period did the first terrestrial vertebrates originate?

The first terrestrial vertebrates originated during the Devonian period.

What purpose do type specimens serve in biological nomenclature?

Type specimens anchor the definition of a species and serve as a reference for future identification.

What is the significance of lignin in bark-bearing trees?

Lignin provides structural support, enabling trees to grow taller and compete effectively for sunlight.

What adaptation does the amniotic egg represent?

The amniotic egg represents an adaptation that allows embryonic development in a terrestrial environment.