Week 1: Life and Diversity

Question 1

What is a species?

Answer 1

A unit of biodiversity and classification and a taxonomic rank.
There are 7 species concepts:

Question 2

Name and define concept 1.

Answer 2

Biological species concept (most used cocept)

Organisms from one species are reproductively isolated from other species

Question 3

What are the issues associated with the biological species concept?

Answer 3

As it is based on the exchange of genetic material via sexual reproduction it is unable to be applied to:

• organisms that reproduce asexually
• organisms that are extinct
• ring species (A –> B –> C –> D etc.) *Describe

Question 4

Name and define concept 2.

Answer 4

Morpho-species concept

Members of the same species look morphologically alike

Question 5

What are the issues associated with the morpho-species concept?

Answer 5

• sexual dimorphism: where males and females of the same species look vastly different
• when young look different to adults of the same species

Question 6

Name and define concept 3.

Answer 6

Ecological species concept

Species are defined by their niche - what resources they use and the environment they inhabit

Question 7

Name and define concept 4.

Answer 7

Phylogenetic species concept

Members of the same species share phylogenetic ancestry

Question 8

Name and define concept 4.

Answer 8

Phylogenetic species concept

Members of the same species share phylogenetic ancestry

Question 9

How many eukaryote species are present on Earth?

Answer 9

Estimated 8.7 million species of which <20% or 1.5 million are named

Question 10

Quantify the approximate microbial abundance on Earth?

Answer 10

~ 10^30 or 1 trillion

Question 11

The most recent estimate of species (eukaryotes and prokaryotes) is…

Answer 11

~10^12

Question 12

List the 4 main reasons biodiversity is so important

Answer 12

1. Human health
2. Agricultural diversity
3. Wild food sources
4. Psychological and moral value

Question 13

Why is there so much more species richness in equatorial/tropical areas?

Answer 13

• Climate stability. More solar radiation and abundant water
• Greater ecosystem age
• More ecological niches/heterogeneity
• Competition and subsequent specialisation = more speciation
• Why!? Enhanced evolutionary capacity

Question 14

An organism’s interaction with abiotic and biotic factors is called its…

Answer 14

Niche