↓ Skip to main content


Overview of attention for article published in BMC Biology, January 2004
Altmetric Badge

About this Attention Score

  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (92nd percentile)

Mentioned by

1 news outlet
1 blog
22 Wikipedia pages
1 video uploader


212 Dimensions

Readers on

325 Mendeley
You are seeing a free-to-access but limited selection of the activity Altmetric has collected about this research output. Click here to find out more.
Published in
BMC Biology, January 2004
DOI 10.1186/1741-7007-2-1
Pubmed ID

Davide Pisani, Laura L Poling, Maureen Lyons-Weiler, S Hedges


The earliest fossil evidence of terrestrial animal activity is from the Ordovician, approximately 450 million years ago (Ma). However, there are earlier animal fossils, and most molecular clocks suggest a deep origin of animal phyla in the Precambrian, leaving open the possibility that animals colonized land much earlier than the Ordovician. To further investigate the time of colonization of land by animals, we sequenced two nuclear genes, glyceraldehyde-3-phosphate dehydrogenase and enolase, in representative arthropods and conducted phylogenetic and molecular clock analyses of those and other available DNA and protein sequence data. To assess the robustness of animal molecular clocks, we estimated the deuterostome-arthropod divergence using the arthropod fossil record for calibration and tunicate instead of vertebrate sequences to represent Deuterostomia. Nine nuclear and 15 mitochondrial genes were used in phylogenetic analyses and 61 genes were used in molecular clock analyses.

Mendeley readers

The data shown below were compiled from readership statistics for 325 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Germany 9 3%
United States 8 2%
United Kingdom 7 2%
Brazil 5 2%
Mexico 3 <1%
Argentina 3 <1%
Portugal 2 <1%
Colombia 2 <1%
Canada 2 <1%
Other 4 1%
Unknown 280 86%

Demographic breakdown

Readers by professional status Count As %
Researcher 80 25%
Student > Ph. D. Student 59 18%
Student > Master 38 12%
Student > Bachelor 27 8%
Professor 25 8%
Other 71 22%
Unknown 25 8%
Readers by discipline Count As %
Agricultural and Biological Sciences 210 65%
Earth and Planetary Sciences 32 10%
Biochemistry, Genetics and Molecular Biology 16 5%
Environmental Science 10 3%
Social Sciences 4 1%
Other 19 6%
Unknown 34 10%

Attention Score in Context

This research output has an Altmetric Attention Score of 19. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 20 July 2021.
All research outputs
of 21,796,779 outputs
Outputs from BMC Biology
of 1,882 outputs
Outputs of similar age
of 323,994 outputs
Outputs of similar age from BMC Biology
of 1 outputs
Altmetric has tracked 21,796,779 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 92nd percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 1,882 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 21.5. This one has gotten more attention than average, scoring higher than 74% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 323,994 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 92% of its contemporaries.
We're also able to compare this research output to 1 others from the same source and published within six weeks on either side of this one. This one has scored higher than all of them