Biology of Mammals

Question 1

Sperm competition in humans

Answer 1

Gallup 2006

Females wait at least 48h after extra-pair copulation before resuming intra-pair copulation.
Changes in post-ejaculatory behaviour to minimise displacement of own sperm

Question 2

Genital morphology linked to social status

Answer 2

Lemaitre 2012

Bank voles: dominant males have wider bacula.
Benefits for sperm competition and/or cryptic female choice. Could also:
- facilitate better placement of copulatory plugs
- increase female stimulation (and therefore fertilisation)
- increase ovulation

Investment in bacula could be condition-dependent?

Question 3

Delayed implantation

Answer 3

Kauffman 2009

Energy status may regulate the timing of implantation.
Delayed implantation may have evolved to buffer against pregnancy failure due to energy imbalance in early gestation.

Question 4

Dog domestication - diet

Answer 4

Arendt 2014

AMY2B gene codes for amylase. Allows dogs to thrive on the high starch diet provided during early domestication. Levels vary across breeds.

Question 5

Dog domestication - East Asian origin

Answer 5

Savolainen 2002

Data suggests common origin from single gene pool. Greatest diversity found in East Asia so originated there?

Question 6

Dog domestication - Bering Land Bridge?

Answer 6

Witt 2014

Most thinking is that humans crossed the Bering Land Bridge with dogs. But dogs not in Americas until 110000bp (humans 15000bp) so dogs didn’t arrive with humans?

Question 7

Cat domestication - Near East

Answer 7

Driscoll 2007

Domesticated in Near East coincided with development of agricultural villages.

Descended from five founders across Near East and then transported by humans across the world.

Question 8

Horse domestication

Answer 8

Anthony and Brown 2011

Secondary products revolution (riding important).

Important role in sheep/cattle farming.

Later useful in warfare.

Question 9

Horse harnessing and milking

Answer 9

Outram 2009

Question 10

Effect of Toxoplasma gondii on human behaviour

Answer 10

Flegr 2007

Those infected with Toxoplasma have higher Testosterone levels.

High T increase risk of Toxoplasma infection?

Or Toxoplasma could manipulate levels of T to impair immunity and increase chance of survival?

Question 11

bTB in cattle - badger culling

Answer 11

Woodroffe 2006

bTB levels higher in areas where culling occurred.

Disrupted territories = movement.

Question 12

Detrimental effects of invasions on small native mammals

Answer 12

McEvoy 2008

Tasmanian swamp rats recognised olfactory cues of native quoll (predator) but not of the non-native invasive red fox/domestic cat.

Question 13

Global warming could increase spread of invasive species

Answer 13

Hobbelen 2013

Hawaiin rock pools

Hawaiin damselfly (predator) vs invasive southern house mosquito (prey).

Global warming could relieve predation pressure and increase spread of invasive species, some of which may be vectors for disease (avian malaria in this case).

Question 14

Human-elephant conflict

Answer 14

Wollman 2012

Deterrents useful where alternative is available. Solutions include culling, contraception, translocation, wildlife corridors.

Need to unify policies across all elephant range countries and cooperate for translocation.

Translocation efficacy unknown.

Question 15

Effects of sociality on survival of juvenile horses

Answer 15

Nunez 2015

Feral horse herds gathered and separated. Survival better amongst foals with greater social networks before separation and more contact with original herd members after separation. More important even than weight! Has sociality evolved to help shield individuals from the effects of catastrophic events?

Question 16

Increased group size alters behaviour of a folivorous primate

Answer 16

Gogarten 2014

Increased group size = decreased time spent feeding and socialising, and increased diet diversity and time spent travelling.

Allows coping with greater scramble competition? Flexibility - increased benefit, decreased cost?

Question 17

Reproductive delays and sperm competition in bats

Answer 17

Orr 2013

Reproductive delays may facilitate sperm competition. Species with reproductive delays had relatively bigger testes (proxy for sperm comp.)

Question 18

Locomotor adaptation in rodents

Semi-aquatic
Arboreal
Fossorial
Ricochetal
Gliding

Answer 18

Samuels 2008

Semi-aquatic - robust bones, enlarged muscular attachments, short femora, elongate hind feet
Arboreal - long humerus and digits, equally proportioned fore and hind limbs
Fossorial - robust bones, enlarged muscle attachments, long manual claws, reduced hind limbs
Ricochetal - disproportionate limbs, proximal inserion of muscles, elongate tibia/hind feet
Gliding - elongate gracile bones, short processes of the ulna, equally proportioned fore and hind limbs.

Question 19

Commercial hunting of marine mammals

Answer 19

Arellano-Perala 2014

Ended isolation of peoples around Baja California Seas

Industrial fisheries and tourism = money.

Need to consider relative contributions of fisheries to tourism, nutrition, social welfare, environmental degradation etc.

Question 20

Devil facial tumour disease and conservation (Genetic diversity)

Answer 20

McCallum 2008

DFTD - loss of genetic diversity threatens populations with disease.
Pathogens with frequency dependent transmission can cause extinction.

Question 21

Disease/invasive species - modelling effects of grey squirrels and squirrelpox virus on red squirrel populations

Answer 21

White 2014

Native species are driven to extinction both with and without disease, but adding disease speeds it up.
Disease can spread through native species even when invading spp is prevented from establishing.
Benefits of increased density negated by increased risk of disease.
Preventing invading species from establishing in strongolds can protect native spp from exclusion but not from disease outbreaks.

Question 22

Sylvatic plague vaccination

Answer 22

Abbott 2012

Question 23

Oxytocin controls birth synchrony in banded mongooses

Answer 23

Hodge 2011

Question 24

Lengthening photoperiod could be the cue for implantation in fur seals

Answer 24

Temte 1985

Question 25

One armed brachiation in gibbon

Answer 25

Gibbons 1982