Webinar about pastclim, an R package to work with palaeoclimate

A couple of days ago, my PI, Prof. Andrea Manica (University of Cambridge), presented a webinar. He talked about pastclim, our piece of software to easily access and manage palaeoclimatic data. He gave a general overview about the palaeoclimatic reconstructions included in it, presented the package and gave examples of how palaeoclimate can be used to address questions related to evolution, palaeoecology and migrations.

Here is the video of the event. You will see some of my work presented there (especially my paper on the palaeoecology of European ungulates).

Mapping Ancient Africa: Andrea Manica “pastclim 1.2: an R package for paleoclimatic reconstructions”

The seminar was part of the project “Mapping Ancient Africa: Climate, Vegetation & Humans“, a multi-year project funded by the Palaeoclimate commission (PALCOM) and Humans & Biosphere commission (HABCOM) within the International Union for Quaternary Research (INQUA).

Teaching for the “Ancient Biomolecules” module, Cambridge Archaeology

During the last couple of weeks, I have been asked by Matthew Collins (Department of Archaeology, University of Cambridge) to contribute two lectures to the module “Ancient Biomolecules”.

In my lecture “Climate and population genetics” I have discussed how to integrate climate into population genetics and genomics, which are the assumptions to take into account, and how to interpret the resulting information. In “The genetics of horse domestication”, I presented and explained a recent paper (Librado et al 2021, Nature) detailing the domestication and spread of Eurasian horses on the basis of ancient DNA data.

It was a lovely occasion, as my talks were followed by many questions and an interesting discussion. I hope there will be other opportunities to collaborate on these topics.

Low ecological differentiation in leopard subspecies

It is now out in bioRxiv the preprint resulting from the part II project of Sidney Leedham:

Sidney Leedham, Johanna L. A. Paijmans, Andrea Manica, Michela Leonardi
Niche conservatism in a generalist felid: low differentiation of the climatic niche among subspecies of the leopard (Panthera pardus)
bioRxiv 2023.01.26.525491

The leopard (Panthera pardus) is a generalist species with a very wide geographic range: it can be found in most of Africa and part of Eurasia. It is subdivided into one African and eight Asian subspecies, which are the result of an ancient expansion from Africa.

We collected published observations of leopards across the entire historical range to see if the Asian subspecies live in the same climate as the African one, or if, in their expansion, they adapted to new climatic conditions.

We visualised the niche occupied by each subspecies in the climate space and compared them to see how much the Asian subspecies diverged from the African one. In most cases, there is great or total overlap, with the exception of the Persian leopard which suggests niche expansion.

This is supported by the fact that, when modelling the range of the species using only African presences, only the most northern part of the distribution is not retrieved.

These results help us better understand how the ecology of the leopard varies across its range, a knowledge that is vital for the effective conservation of its most distinct and vulnerable populations.

Preprint

Sidney Leedham, Johanna L. A. Paijmans, Andrea Manica, Michela Leonardi
Niche conservatism in a generalist felid: low differentiation of the climatic niche among subspecies of the leopard (Panthera pardus)
bioRxiv 2023.01.26.525491. doi: https://doi.org/10.1101/2023.01.26.525491

Abstract

Aim Species distribution modelling can be used to reveal if the ecology of a species varies across its range, to investigate if range expansions entailed niche shifts, and to help assess ecological differentiation: the answers to such questions are vital for effective conservation. The leopard (Panthera pardus spp.) is a generalist species composed of one African and eight Asian subspecies, reflecting dispersal from an ancestral African range. This study uses species distribution models to compare the niches of leopard subspecies, to investigate if they conserved their niches when moving into new territories or adapted to local conditions and shifted niche.

Location Africa and Eurasia

Methods We assembled a database of P. pardus spp. presences. We then associated them with bioclimatic variables to identify which are relevant in predicting the distribution of the leopard. We then constructed a species distribution model and compared the distribution predicted from models based on presences from all subspecies versus the ones built only using African leopards. Finally, we used multivariate analysis to visualise the niche occupied by each subspecies in the climate space, and to compare niche overlaps to assess ecological differentiation.

Results Niche comparisons and model predictions suggest a general lack of niche separation between all subspecies. Most Asian subspecies have overlapping niches and occupy subsets of the niche of the African leopard. Nevertheless, we found the Persian leopard Panthera pardus saxicolor to have the most distinct niche, giving some evidence for niche expansion in more Northern Asian subspecies.

Main conclusions These results suggest little ecological differentiation among leopard subspecies and a lack of adaptation to novel climates after dispersal from Africa. This finding complements recent genetic studies in implying that the taxonomy of Asian leopards may not reflect biological differentiation, an issue that is important to resolve due to its relevance for the conservation of the species.

pastclim v. 1.2 and paper

pastclim, our R package to easily access and use paleoclimatic reconstructions has now been updated to version 1.2. Moreover, is now out in Ecography the paper describing it:

Michela Leonardi, Emily Y. Hallett, Robert Beyer, Mario Krapp, Andrea Manica
pastclim 1.2: an R package to easily access and use paleoclimatic reconstructions
Ecography, First published: 05 January 2023 https://doi.org/10.1111/ecog.06481

Here is a list of what is new compared to the preprint:

  • pastclim is now on CRAN: https://cran.r-project.org/web/packages/pastclim/index.html;
  • We have added functions to crop based on an extent or a mask, and to randomly sample points across space and/or time;
  • We added a cheatsheet summarising the main functions;
  • A new vignette shows how to work with custom data and how to add them to the package in order for them to be available for all users.

Here is a table summarising the functions used in the package

Download the data
get_data_path()Retrieve the path in which pastclim automatically stores the data
set_data_path()Store the data in a custom path
download_dataset()Download a whole dataset (all variables available)
get_vars_for_dataset()
Download variables of choice for a given dataset
Download variables of choice for a given dataset
get_downloaded_datasets()Summary of the downloaded variables
get_time_steps()List of time steps available in a given dataset
Get climate for locations or regions
location_slice()Get the climate for given locations (by coordinates and age)
location_series()Get time series of the climate for given locations
region_slice()get the climate for a given region in a given time step
sample_region_slice()sample a given number of points from the climate of a region
region_series()get the time series of the climate for a given region
sample_region_series()sample a given series of points from the time series of a region
Working with biomes and ice sheets
get_biome_classes()legend of the ‘biome’ categorical variable, when available
get_ice_mask()get a mask with the extent of the ice sheets for a given time step
get_land_mask()get a mask with the extent of the land masses for a given time step
Vignettes
vignette(“pastclim_overview”, package = “pastclim”)overview of pastclim
vignette(“custom_datasets”, package = “pastclim”)how to add a new dataset to pastclim
vignette(“available_datasets”, package = “pastclim”)list of datasets available

More info:

website: https://evolecolgroup.github.io/pastclim/index.html
manual: https://rdrr.io/github/EvolEcolGroup/pastclim/
GitHub repository: https://github.com/EvolEcolGroup/pastclim
CRAN: https://cran.r-project.org/web/packages/pastclim/index.html
vignette: https://evolecolgroup.github.io/pastclim/articles/a0_pastclim_overview.html
cheatsheet: evolecolgroup.github.io/pastclim/pastclim_cheatsheet.pdf

If something does not work

You can raise an issue here