Tag Archives: Evolution

Major transitions in human evolution – Advanced Seminar in Palaeobiology

We are pleased to announce:

Major transitions in human evolution – Advanced Seminar in Palaeobiology (54261)
Dates: 4.11.–16.12.
Time: Fridays 12.15-13.45 p.m.
Building/room: Physicum, D112,  Kumpula Campus Number of places: max. 30
Credits: 2-4

This seminar series will focus on the issues concerning human evolution addressed in recently published special paper compilation (http://rstb.royalsocietypublishing.org/content/371/1698) and other relevant papers (including: http://www.isita-org.com/jass/Contents/ContentsVol94.htm):

Middle Pliocene hominin diversity – An earlier origin for stone tool making: implications for cognitive evolution and the transition to Homo – Morphological variation in Homo erectus and the origins of developmental plasticity – The evolution of body size and shape in the human career – The place of Homo floresiensis in human evolution – Filling the gap: Human cranial remains from Gombore II and the origin of Homo heidelbergensis – The origin and evolution of Homo sapiens – The transition to foraging for dense and predictable resources and its impact on the evolution of modern humans

You can get credit points for each of the following: Seminar presentation (compulsory, 2 credit points); Active participation in 75% of the classes verified by a personal seminar diary (1 credit point); writing an essay (1 credit point). The seminar thus yields a total of 2-4 credit points.

Please sign up for the course at weboodi (course code: 54261).

Sincerely,
Laura Säilä & Mikael Fortelius

Purgatorius and Darwin’s finches

Oldest known euarchontan tarsals and affinities of Paleocene Purgatorius to Primates

Stephen G. B. Chester, Jonathan I. Bloch, Doug M. Boyer, and William A. Clemens

http://www.pnas.org/content/112/5/1487

Purgatorius has been considered a plausible ancestor for primates since it was discovered, but this fossil mammal has been known only from teeth and jaw fragments. We attribute to Purgatorius the first (to our knowledge) nondental remains (ankle bones) which were discovered in the same ∼65-million-year-old deposits as dentitions of this putative primate. This attribution is based mainly on size and unique anatomical specializations known among living euarchontan mammals (primates, treeshrews, colugos) and fossil plesiadapiforms. Results of phylogenetic analyses that incorporate new data from these fossils support Purgatorius as the geologically oldest known primate. These recently discovered tarsals have specialized features for mobility and provide the oldest fossil evidence that suggests arboreality played a key role in earliest primate evolution.

Evolution of Darwin’s finches and their beaks revealed by genome sequencing

Sangeet Lamichhaney, Jonas Berglund, Markus Sällman Almén, Khurram Maqbool, Manfred Grabherr, Alvaro Martinez-Barrio,    Marta Promerová, Carl-Johan Rubin, Chao Wang, Neda Zamani, B. Rosemary Grant, Peter R. Grant, Matthew T. Webster    & Leif Andersson

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14181.html

Darwin’s finches, inhabiting the Galápagos archipelago and Cocos Island, constitute an iconic model for studies of speciation and adaptive evolution. Here we report the results of whole-genome re-sequencing of 120 individuals representing all of the Darwin’s finch species and two close relatives. Phylogenetic analysis reveals important discrepancies with the phenotype-based taxonomy. We find extensive evidence for interspecific gene flow throughout the radiation. Hybridization has given rise to species of mixed ancestry. A 240 kilobase haplotype encompassing the ALX1 gene that encodes a transcription factor affecting craniofacial development is strongly associated with beak shape diversity across Darwin’s finch species as well as within the medium ground finch (Geospiza fortis), a species that has undergone rapid evolution of beak shape in response to environmental changes. The ALX1 haplotype has contributed to diversification of beak shapes among the Darwin’s finches and, thereby, to an expanded utilization of food resources.

– Jackie

Molluscan spikes explained by physical properties of the growing mantle!

Hi,

That paper might interest some of you

Mechanical basis of morphogenesis and convergent
evolution of spiny seashells
Régis Chirat, Derek E. Moultonb, and Alain Goriely

Abstract

Convergent evolution is a phenomenon whereby similar traits
evolved independently in not closely related species, and is often
interpreted in functional terms. Spines in mollusk seashells are
classically interpreted as having repeatedly evolved as a defense in
response to shell-crushing predators. Here we consider the morphogenetic
process that shapes these structures and underlies their
repeated emergence. We develop a mathematical model for spine
morphogenesis based on the mechanical interaction between the
secreting mantle edge and the calcified shell edge to which the
mantle adheres during shell growth. It is demonstrated that a large
diversity of spine structures can be accounted for through small
variations in control parameters of this natural mechanical process.
This physical mechanism suggests that convergent evolution of
spines can be understood through a generic morphogenetic process,
and provides unique perspectives in understanding the phenotypic
evolution of this second largest phylum in the animal kingdom.

Best,
Elodie

Lecture by Manfred Laubichler

VIIKKI BIOCENTER LECTURE
NOTE TIME: on Tuesday, March 26 at 10.15
Auditorium 1041, Biocenter 2
http://www.biocenter.helsinki.fi/viikki_lectures.html

Manfred Laubichler (Arizona State University, USA): The past, present and future of developmental evolution: A drama in three acts

Host: Jukka Jernvall

Manfred Laubichler’s research covers three areas. His work in theoretical biology is focused on conceptual and mathematical issues, such as the problem of defining biological characters in development and evolution, the homology problem, and the theory of epistatic and epigenetic effects. In evolutionary developmental biology Laubichler focuses on social insects as a model system. Finally, he is interested in the history of theoretical biology, embryology and developmental biology. In his presentation, Laubichler will discuss broadly issues related to molecular and computational challenges in developmental evolution studies.

Dr. Laubichler is Professor of Theoretical Biology and History of Biology; Director, Center for Social Dynamics and Complexity; Associate Director, Origins Project; Adjunct Scientist, Marine Biological Laboratory, Woods Hole; External Professor, Santa Fe Institute.

Selected references:
http://www.youtube.com/watch?v=tR2dLrvFx7c

Hartfelder et al., (2012) Development and evolution of caste dimorphism in honeybees – a modeling approach. Ecology and Evolution 2: 3098-3109.
Linksvayer et al., (2012) Developmental Evolution in Social Insects: Regulatory Networks from Genes to Societies. J. Exp. Zool. Part B-Mol. Dev. Evol. 318B: 159-169.
Maienschein and Laubichler (2010) The Embryo Project: An Integrated Approach to History, Practices, and Social Contexts of Embryo Research. J. Hist. Biol. 43: 1-16.
Laubichler  and Maienschein (eds) (2009) Form And Function In Developmental Evolution. Cambridge Studies in Philosophy and Biology.
Laubichler et al. (2005) The Concept of Strategies and John Maynard Smith´s Influence on Theoretical Biology. Biology and Philosophy 20: 1041-1050.