Introduction to evolution, biodiversity and deep time

Question 1

Basic concepts of neo-Darwinian evolution

Answer 1

Neo-Darwinian - Darwin’s theory of evolution with Mendel’s theory of heredity attached

six propositions:
-Reproduction
All organisms have the ability to reproduce and produce offspring with genetic variation

-Excess
Most populations produce more offspring than can survive to adulthood. This leads to competition for resources and survival of the fittest

-Variation
Genetic variation exists within a population due to mutations, genetic recombination, and gene flow

-Environmental selection (natural selection)
The environment acts as a selective force, favouring certain traits that increase an organism’s chances of survival and reproduction. This leads to differential reproduction of individuals with advantageous traits and eventually results in the adaptation of populations to their environment

-Divergence
Over time, populations can become isolated from each other and diverge genetically due to different selective pressures or random genetic drift
Caused by natural selection

-Ancestry
All living organisms share a common ancestor and have descended with modification from that ancestor over billions of years

Question 2

An introduction to biodiversity - definition

Answer 2

Biodiversity is the variety of life, in all manifestations it encompasses all forms, levels, and combinations of natural variation

Question 3

Deep time and its classification

Answer 3

the vast expanse of geologic time
It encompasses the billions of years of Earth’s history and the evolution of life on our planet

Question 4

Eons & eras through time

Answer 4

Precambrian Eon:
Earliest stage of Earth’s history, from the formation of the planet 4.6 billion years ago to the beginning of the Paleozoic Era
This eon is further divided into three eras: Hadean, Archean, and Proterozoic.

Paleozoic Era:
From 541 to 252 million years ago, characterised by the evolution of many diverse and complex life forms, including fish, amphibians, reptiles, and insects.
It is divided into six periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian.

Mesozoic Era: Spans from 252 to 66 million years ago and is known as the “Age of Dinosaurs”.
It is divided into three periods: Triassic, Jurassic, and Cretaceous.

Cenozoic Era: Spans from 66 million years ago to the present and is characterised by the evolution of mammals, birds, and flowering plants.
It is divided into two periods: Paleogene and Neogene, which are further divided into epochs.

Question 5

Taxonomy and phylogeny with a time dimension

Answer 5

Taxonomy can provide insights into the evolutionary relationships between different organisms, as organisms with similar physical and genetic characteristics are likely to share a common ancestor.

Phylogenetic analyses also allow scientists to infer the timing of evolutionary events and the rates of change in different lineages over time.

Question 6

Environmental change through time

Answer 6

Long term
-Distance between earth and moon
-Continental drift
-Climate change

Short/medium term
-Super eruptions
-Tsunamis
-Mass extinctions