microevolution of a red squirrel population caused by climate change
DESCRIPTION
Microevolution of a red squirrel population caused by climate change. Vincent Arcega April 23, 2013. Phylogeny. Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Rodentia Family: Sciuridae Genus: Tamiasciurus Species: T . hudsonicus. Facts. Length30 cm Weight 280 g - PowerPoint PPT PresentationTRANSCRIPT
Microevolution of a red squirrel population caused by climate change
Vincent ArcegaApril 23, 2013
PhylogenyKingdom:AnimaliaPhylum:ChordataClass:MammaliaOrder:RodentiaFamily:SciuridaeGenus:TamiasciurusSpecies:T. hudsonicus
FactsLength30 cmWeight 280 gLifespan 6 yearsHabitat trees
DietConifer seeds, flowers, berries.
Predation Birds, lynx, coyotes.
www.en.wikipedia.org
Genetic and plastic responses of a northern mammal to climate change
Authors:Denis Reale, Andrew G. McAdam,
Stan Boutin and Dominique Bertaeaux
Genetic and plastic responses of a northern mammal to climate change
As climate increases due to global warming animals must cope through physiological changes or microevolution.
Purpose of studyMicroevolution is the changes
in allele frequencies that occur over time within a population. This change is due to four different processes: mutation, selection (natural and artificial), gene flow, and genetic drift.
Purpose of studyRed squirrels are studied for how
they have adapted to the climate change with changes in spring weather and food abundance.
Purpose of StudyBreeding was documented over
four generations.Parturition date is hereditary. If
parturition date changes then the results may be from microevolution.
Life span of Red Squirrel?
ReproductionRed squirrels breed once or twice
a year, depending on their geographic location
The breeding season begins in midwinter from March to May. Followed by August to early September.
Reproduction* Females are in estrus only 1
day per breeding season!Conception usually occurs within
a few hours of mating.
Climate ChangeEarth's average temperature has
risen by 1.4°F over the past century, and is projected to rise another 2 to 11.5°F over the next hundred years
(www.epa.gov)
www. epa.gov
The orange line shows the first arrival of frost in the fall, which is occurring later in the year than previously. The green line shows the timing of the last spring frost, which is occurring earlier in the year than previously.
Material and MethodsThe study was near Kluane Lake,
Yukon, Canada. The habitat was open boreal forest
325 squirrels were ear-taggedReproductive activity monitored
yearly.
Breeding ValueThis represents the combined
additive effects of all an individual’s genes for a given trait and changes in estimated breeding values (EBVs).
Breeding ValueThis approach helps differentiate
between temporal phenotypic changes due to genetic and environmental sources
Environmental changes and reproductionFemales born in 1989 and 1998
lifetime parturition date was calculated.
Food is counted every August.Yearly spruce cones were a
measure of the average food abundance.
Maternal EffectsFive maternal characteristics that
may affect EBV:Maternal AgeLitter SizePostpartum body massMaternal reproductive
investmentSpruce cone index.
Microevolutionary changes in parturition dateFemales born in 1989 and 1991
were assigned generation oneFemales after 1991 regardless of
the year born were 1 generation higher than their mother.
Results Factor: EnvironmentSpring temperature has increased by nearly
2˚ CNo particular trend for precipitationNumber of cones have increased by over 35%
Note: For weather temperatures you can make a rough conversion from Celsius to Fahrenheit by doubling the figure and adding 30.
Results Factor: ReproductionThe past decade has shown
advance increase in parturition date.
Red squirrels born in 1989: from January 1 to May 8 (128 days).
Results Factor: ReproductionRed squirrels born in 1998: from
January 1 to April 20 (110 days)
128 days – 110 days = 18 daysReproduction has changed 18
days in the past decade.
Phenotypic PlasticityFood abundance had large effect
on reproduction.This indicates a large amount of
phenotypic plasticity and a strong effect on breeding.
Figure 1
Figure 2 Figure 3
In ConclusionIn the past 27 years Yukon has
increased in spring temperatures and also an increase in food.
The response was an 18 day advancement in breeding.
The red squirrels have experienced phenotypic changes and microevoltuion.
In ConclusionFrom the author:
“The combination of phenotypic changes within generations and microevolutionary changes among generations resulted in large phenotypic responses to rapid changes in environmental conditions experienced by this population of squirrels over the past 10 years.”
Questions, Comments, Concerns.