Grimaldi and Engel 2005 Current Views on Diversity

Mina Krenz Dan Chou Phylogenomics resolves the timing and paern of insect evolution

Misof B. et al 2014

Why Study Insect Phylogeny? • represent one of the earliest to make their way to terrestrial and aquatic environments • Due to having a multitude of species, the phylogeny of insects are still well debated to this day • Must reconstruct timelines of insect diversification in order to understand the changes in their physiology and morphology Summary of the methods • 1478 nuclear genes from 144 extant taxa • More than 2.5 gigabases from each of the 103 species they studied • Estimating divergence events via 37 fossil records • Maximum Likelihood of mutations in DNA and amino acids (rather than maximum parsimony) Boot-Strapping • Acts as a resampling method in statistics • Selects a number of base pairs to see how sensitive results are to exclusion of some data. • Resampling data to see how robust and strong it is against randomization. • See conflict in data by providing: confidence intervals, variance, errors, etc. Paleoptera Relationship between Odonates and Ephemeroptera • The data indicates that Odonata and Ephemeroptera are nested within the Paleoptera • However, this analysis is supported by a low boot- strapping • What might this mean? o Odonates and Ephemeroptera possibly paraphyletic? • Why is it difficult to determine the relationships in Paleoptera? Relationship between Odonates and Ephemeroptera

• Paleoptera only have two extant lineages, even though they derive from all the way back in the Carboniferous • Most likely Odonata and Ephemeroptera divided shortly after Paleoptera and Neoptera diverged, so huge variance between two Orders • Long time span for Ephemeroptera and Odonata to diverge through gene mutations Neoptera

Polyneoptera, Holometabola/Endometabolous and Paraneoptera*** Holometabolous • Strong statistical support for the well-nested group of Holometabolous • High diversity of , Diptera, and Lepidoptera in early Cretaceous Polyneoptera • Previous study supported the monophyly in groups such as Hexapoda, Insecta, Pterygota, Neoptera, Paraneoptera, and Holometabolous • However, there was weaker support for a monophyletic Polyneoptera (Kjer et al 2006)

Polyneoptera • Misof et al strongly support the monophyletic group of the Polyneoptera • Boom in diversity of Blattodea, Mantodea, and Plasmodea in Permean extinction. Polyneoptera

Holometabolous /Endopterygota Paraneoptera • The results suggest a diverge of Psocodea from the rest of the Paraneoptera, forming a paraphyletic group • The results show that Psocodea in fact a sister taxa to the Holometabolous • Yet this claim does not have statistical support • Why include this data if it is not backed? Age of Psocodea Taxa? • The study claims that that parasitic lice (Menopan and Pediculus) arose in around 53mya with the emergence of the avian and mammalian taxa. • However, their analysis looks at the crown clade, rather than the stem clade from the remaining • Stem shows an arrival of parasitic lice ~130 mya, at the arrival of feathered theropod dinosaurs

Food for Thought • In your opinion, how to these results compare to what has been presented in class/in the book (i.e. what critiques do you have for this study)? • What other data or tests could have been used to make this study more reliable? • Study of genomics is still a fairly new field of science • Science based on certain assumptions and interpretations of the data; continuously changing and growing Gullan and Cranston, 2014 Food for Thought • What evolutionary/environmental factors may have given rise to these diverse groups? Phylogeny of the : Diversificaon in the Age of Angiosperms Moreau C.S., Bell C.D., Vila R., Archibald B., Pierce N.E. Ants

• Key roles in symbioc interacons • Soil Aeraon • Nutrient cycling • Dominant in terrestrial landscape: – 11,800 species – evoluonary history poorly resolved Main points

• Extant ants arose much earlier than previously proposed: 75-125 mya • Began to diversify late Cretaceous – Early Eocene – 60-100 mya • This me period corresponds with the rise of angiosperms and many herbivorous insects Past phylogenies of Family Formicidae

• Past phylogenies proposed using morphological traits and molecular data with less data • This phylogeny constructed from large-scale molecular data – 4.5 kb of sequence data – Six gene regions from 139 of 288 extant genera • Represents 19 of 20 subfamilies Stascal Analysis

• Maximum likelihood bootstrap • Bayesian posterior probabilies • Maximum parsimony bootstrap Major lineages in Formicidae

• Three main clades: – Leptanilloid (sister taxon to all other ants) • One subfamily: – Poneroid • 5 subfamilies • lacked support – Formicoid • Contains remaining 13 subfamilies

Monophyly • 14 recovered as Monophylec with strong support – Leptanillinae (100%) • Early morphological phylogenies do not show this at basal posion • Basal posion shows early tergosternal fusion of 3rd & 4th abdominal segments, lost secondarily • These characters are labile/homoplasious • 19 recovered as monophylec • Cerapachyinae paraphyly

Bolton = Proposed “poneromorph” clade -Amblyoponinae - - -Paraponerinae - -Procerinae

These results exclude Ectatomminae and Heteroponerinae, but add -Represented by Tatuidris Tatusia

Bolton = Proposed “poneromorph” clade using morphological analyses -Amblyoponinae -Ectatomminae -Heteroponerinae -Paraponerinae -Ponerinae -Procerinae

These results exclude Ectatomminae and Heteroponerinae, but add Agroecomyrmecinae

Historical placement of Heteroponerinae and Ectatomminae • Heteroponerinae in formicoid clade is unexpected – Historically in poneromorph clade – Same goes for Ectatomminae (closely related to Heteroponerinae) Fossil record

• Oldest reliable fossils containing Formicidae are ~100 million yrs. old from early cretaceous in French & Burnese ambers • Implies earlier history than expected of Formicidae • Results show an even earlier history…

140-168 Million years old! Much older than previous esmate based on fossil record Previous studies showing early history of Formicidae • Previous studies by Brady and Ward used molecular data to arrive at an esmate of 130-140 Million years old – But…. Although these are similar dates the Moreau et al. study used: • Wider sampling • Addional fossils à Leads to an even older esmate! (140-168 mil years old) Results • Diversificaon of major Formicidae lineages ocurred: – beginning of Early Paleoceneto Late cretaceous (60-100 Mya) • Ancestors of major subfamilies present 75-125 mya • If they were present much earlier, why did they take so long to diversify? • Previous fossil record indicates later evoluon

Correspondence with Angiosperm radiaon • Rise in Angiosperm dominated forests was essenal to the diversificaon of ants – Why would this happen?

Discussion

Given the importance of plants in determining the ming of evolved traits in insects, as well as human’s adverse impact on nature (eg: deforestaon), is it possible that insect evoluon is being dampened? Would insects be beer off without humans or are all organisms interconnected and important for others to thrive, despite some downfalls?

Lineages through me plot

• LTT plot: Accumulaon of lineages around ~100 (following angiosperm radiaon) – Also seen in Coleopteran & Hemipteran diversificaon Is there something wrong with the way this Histogram was constructed? Are LTT graphs a good method for researchers to infer phylogenec relaonships? Why or why not? Why the correlaon between Angiosperm radiaon and diversificaon of Formicidae?

• Forests are more diverse – Wider array of habitats • Expansion of herbivorous insects – Provided direct food source – Indirect food source: honeydew – Shi in diet à evoluon of social behaviors

Significance?

• Evoluonary invesgaon of life history, ecology, biogeography in order to: – Observe paerns of diversificaon and distribuon of this dominant group of insects • This highlights need for conservaon of ant habitats to foster biodiversity to further research poorly understood evoluonary history The Fossil record and Macroevoluonary history of beetles Smith D.M. and Marcot J.D. Main points • Compiled a database of global beetle fossil data in order to study evoluonary history • Polyphaga responsible for most taxononmic richness of beetles – Also increase in diversificaon rate in Cretaceous like Formicidae, but not due to Angiosperm radiaon • Observed mechanisms that inhibited beetle exncon rather than mechanisms promong speciaon Polyphagan vs. Non-Polyphagan diversificaon • Degree of dietary variaon and specializaon within subgroups in Polyphaga – Algae, fluid feeders, carnivores, xylophages • Non-polyphagans first to appear in fossil record – Reach peak of family richness in Triassic – Jurassic: low originaon rates and higher exncon rates than Polyphaga • Polyphagans surpass richness of non- polyphagans in Jurassic – Established early and longlived (family exncon rate of zero) Increase in diversificaon rate of Polyphagans Polyphagans diversificaon rate surpasses that of non-polyphagans (who have a higher exncon rate in this me period) Non-polyphagans reach family richness peak

Origin of non-polyphagans

Should this middle-cretacean increase in the diversificaon rate of Polyphagans be aributed to the rise in Angiosperms during the same me period? Like that of the Ant paper?

Amber deposits

• Instead of aribung this to Angiosperm radiaon, Smith and Marcot connect this pulse of Polyphagan originaon to: – First ocurrence of beetle-bearing amber deposits in fossil record – They used different types of fossils in their database: lacustrine deposits

Why Polyphaga beetles may not be as suscepble to exncon

• Ability to change geographical distribuon in response to climate change – Diet

Discussion

Why must phylogenies always be regarded as working hypotheses and considered with a certain level of scruny?

References • Main Papers: o Misof et al. 2014. Phylogenomics resolves the timing and pattern of insect evolution. Science 346.620: 763-767 o Moreau C.S., Bell C.D., Vila R., Archibald S.B, Pierce N.E.. 2006. Phylogeny of the Ants: Diversification in the Age of Angiosperms. Science 312: 101-104. • Resources: o Grimaldi D. and Engel M.S. 2005. Evolution of the Insects. Cambridge University Press: New York. o Kjer K.M. Carle F.L. Litman J., and Ware J. 2006. A Molecular Phylogeny of Hexapoda. Systematics & Phylogeny 61(1): 35-44. o Smith D.M and Marcot J.D. 2015. The fossil record and macroevolutionary history of the beetles. Proc. R. Soc. B 282: 1-8.