Biodiversity Science

Protecting biodiversity is a goal of most people who value the environment. My question is what are the goals of biodiversity science and how do we achieve them? Some history is in order here. The term ‘biodiversity’ was coined in the 1980s as the complete biosphere including all species and ecosystems on Earth. The idea of cataloguing all the species on Earth was present many decades before this time, since the origin of the biological sciences. By the 1990s ‘biodiversity conservation’ became a popular subject and has grown greatly since then as a companion to CO2 emissions and the climate change problem. The twin broad goals of biodiversity science and biodiversity conservation are (1) to name and describe all the species on Earth, and (2), to protect all species from extinction, preventing a loss of biodiversity. How can we achieve these two goals?

The first goal of describing species faces challenges from disagreements over what a species is or is not. The old description of a species was to describe what group it was part of, and then how different this particular species was from other members of the group. In the good old days this was primarily based on reproductive incompatibility between species, if no successful reproduction, must be a new species. This simple common-sense view was subject to many attacks since some organisms that we see as different can in fact interbreed. Lions and tigers breed together and are an example, but if their interbred offspring are sterile, clearly, they are two different species. But many arguments arose because there was no data available for 99% of species to know if they could interbreed or not. The fallback position has been to describe the anatomy of a potential species and its relatives and judge from anatomy how different they were. Endless arguments followed, egged on by naturalists who pointed out that if the elephants in India were separated by a continent from elephants in Africa, clearly, they must be different species defined by geography. Many academic wars were fought over these issues.

Then in 1953 the structure of DNA was unravelled, and a new era dawned because with advances in technology of decoding genes we could describe species in a completely new way by determining how much DNA they had in common. But what is the magic percentage of common DNA? Humans and chimpanzees have 98.6% of their DNA in common, but despite this high similarity no one argues that they are the same species.

Despite this uncertainty the answer now seems much simpler: sequence the DNA of everything and you will have the true tree of life for defining separate species. While this was a dream 20 years ago, it is now a technical reality with rapid sequencing methods to help us get criminals and define species. Problem (1) solved?

Enter the lonely ecologist into this fray. Ecologists do not just want names, they wish to understand the function of each of the ‘species’ within communities and ecosystems, how does all this biodiversity interact to produce what we see in the landscape? For the moment we have approximately 10 million species on Earth, but somewhere around 80% of these ‘species’ are still undescribed. So now we have a clash of biodiversity visions, we cannot describe all the species on Earth even on the time scale of centuries, so we cannot achieve goal (1) of biodiversity science in any reasonable time. We have measured the DNA sequence of thousands of organisms that we can capture but we cannot describe them formally as species in the older sense. Perhaps it is akin to having all the phone numbers in the New York City phone book but not knowing to whom the numbers belong.

But the more immediate problem comes with objective (2) to prevent extinctions. Enter the conservation ecologist. The first problem is discussed above, we ecologists have no way of knowing how many species are in danger of extinction. We must look for rare or declining species, but we have complete inventory for few places on Earth. We must concentrate on large mammals and birds, and hope that they act as umbrella species and represent all of biodiversity. When we do have information on threatened species, for the most part there is no money to do the ecological studies needed to reverse declines in abundance. If there is money to list species and give a recovery plan on paper, then we find there is no money to implement the recovery plan. The Species-At-Risk act in Canada was passed in 2002 and has generated many recovery plans mostly for vertebrate species that have come to their attention. Almost none of these recovery plans have been completed, so in general we are all in favour of preventing extinctions but only it if costs us nothing. By and large the politics of preventing extinctions is very strongly supported, but the economic value of extinctions is nearly zero.

None of this is very cheery to conservation biologists. Two approaches have been suggested. The first is Big Science, use satellites and drones to scan the Earth every year to describe changes in landscapes and from these images infer biodiversity ‘health’. Simple and very expensive with AI to the rescue. But while we can see largescale landscape changes, the crux is to do something about them, and it is here that we fail because of the wall of climate change that we have no control over at present. Big Science may well assist us in seeing patterns of change, but it produces no path to understanding food webs or mediating changes in threatened populations. The second is small-scale biodiversity studies that focus on what species are present, how their numbers are changing, and what are the causes of change. Difficult, possible, but very expensive because you must put biologists in the field, on the ground to do the relevant measurements over a long-time frame. The techniques are there to use, thanks to much work on ecological methods in the past. What is missing again is the money. There are a few good examples of this small-scale approach but without good organization and good funding many of these attempts stop after too few years of data.

We are left with a dilemma of a particular science, Biodiversity Science, that has no way of achieving either of its two main objectives to name and to protect species on a global level. On a local level we can adopt partial methods of success by designating and protecting national parks and marine protected areas, and by studying only a few important species, the keystone species of food webs. But then we need extensive research to determine how to protect these areas and species from the inexorable march of climate change, which has singlehandedly complicated achieving biodiversity science’s two goals. Alas at the present time we may have another science to join the description of economics as a “dismal science” And we have not even started to discuss bacteria, viruses, and fungi.

Coffey, B. & Wescott, G. (2010) New directions in biodiversity policy and governance? A critique of Victoria’s Land and Biodiversity White Paper. Australasian Journal of Environmental Management 17: 204-214. doi: 10.1080/14486563.2010.9725268.

Donfrancesco, V., Allen, B.L., Appleby, R., et al. (2023) Understanding conflict among experts working on controversial species: A case study on the Australian dingo. Conservation Science and Practice 5: e12900. doi: 10.1111/csp2.12900.

Ritchie, J., Skerrett, M. & Glasgow, A. (2023) Young people’s climate leadership in Aotearoa. Journal of Peace Education, 12-2023: 1-23. doi: 10.1080/17400201.2023.2289649.

Sengupta, A., Bhan, M., Bhatia, S., Joshi, A., Kuriakose, S. & Seshadri, K.S. (2024) Realizing “30 × 30” in India: The potential, the challenges, and the way forward. Conservation Letters 2024, e13004. doi: 10.1111/conl.13004.

Wang, Q., Li, X.C. & Zhou, X.H. (2023) New shortcut for conservation: The combination management strategy of “keystone species” plus “umbrella species” based on food web structure. Biological Conservation 286: 110265.doi. 10.1016/j.biocon.2023.110265.

6 thoughts on “Biodiversity Science

  1. Matti Nummelin

    I am not sure what is the problem here. It is clear that we cannot name and to protect all species on a global level during our time or ever in future. However, we can move towards more or less right direction. In environmental movement and in this case biodiversity science, I prefer incrementalism. As google describes it: “In public policy, incrementalism is the method of change by which many small policy changes are enacted over time in order to create a larger broad based policy change.” I wouldn´t call it “dismal science”. Some steps are small, but also huge leaps can be achieved.
    Matti Nummelin, Chair IUCN National Committee, Finland, and Secretary Finnish Climate Grandparents.

    1. Charles Krebs Post author

      Dr. Nummelin – I agree with you completely, we do what we can do and move ahead slowly. My reaction in this blog was perhaps aimed more at the North American news market in which articles appear in highlight that we will be able to do a complete inventory of life on Earth with DNA technology, and this will somehow solve the conservation crisis. I think optimism should be realistic and wild optimism should be controlled lest the person-on-the-street be convinced via the media that all is in safe hands. So I seek a middle road between the extremes of pessimism (all is lost) and optimism (all is saved). And at least in North America conservation has been a political football of too much talk and too little action. Thanks for your comments.

  2. Maria

    how can interdisciplinary collaboration be optimized to propel us closer to the twin goals of naming and protecting Earth’s myriad species?

  3. Michael Baumann

    (I know, I know, too long again. I always seem to drag myself into a swamp of thoughts.)

    How much biodiversity is out there?
    Why are there so many species (1), or why are there so few (2)?
    Why is biodiversity worth protecting?
    How should we manage biodiversity?

    These are the questions of biodiversity science, of course, but I am afraid that we will fail at the first one. Answering how much biodiversity is out there does require taxonomists.

    It is not a secret that around the time of the Watson and Crick paper in 1953 (3), a chasm opened in biology, a chasm between molecular biology and organismic biology. Molecular biology received faculty positions, research funding, research castles, and journals (4). Organismic biology received a kick in the groin.

    In their classic paper from 1979 — 1979!! — Gould and Lewontin quote Rupert Riedl (5):

    “[T]he whole of the huge and profound thought collected in the field of morphology, from Goethe to Remane, has virtually been cut off from modern biology. It is not taught in most American universities. Even the teachers who could teach it have disappeared.”

    (I received my undergraduate training under Rupert Riedl at the University of Vienna. A lot of courses in morphology and comparative anatomy, a lot of Linnean tables and classification keys, nothing on cladistics, very little biochemistry. But even as zoologists we had to be able to identify at least 125 plant species (6).)

    The situation wasn’t helped when in 1988 Nobel laureate Luis Alvarez disparaged the scientists who try to understand species (7):

    “I don’t like to say bad things about paleontologists, but they’re really not very good scientists. They’re more like stamp collectors.”

    Except, of course, Alvarez did say a lot of “bad things” about other scientists.

    Taxonomists used to be respected as collectors of historical evidence to test hypotheses on the origins of species, disparity in body plans, biodiversity, variation within species, and, more recently, invasive species (8). There is no comfort in the irony that the profession that can tell us whether a species is going extinct is going extinct itself.

    Maybe I don’t know enough, or maybe my judgement is too harsh. I am wondering, Charley, how do you see recruitment and training in biodiversity science?

    (1) G. E. Hutchinson (1959), Homage to Santa Rosalia or Why Are There So Many Kinds of Animals. The American Naturalist 93(870): 145 – 159
    (2) J. Felsenstein (1981), Skepticism Towards Santa Rosalia, or Why Are There So Few Kinds of Animals. Evolution 35:124 – 138
    (3) J.D. Watson and F.H.C. Crick (1953), Molecular Structure of Nucleic Acids. Nature 171: 737 – 738
    (4) Have a look: (Accessed: 7 Mar 2024). How many Nature journals cover molecular biology, how many organismic biology?
    (5) S.J. Gould and R.C. Lewontin (1979), The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proceedings of the Royal Society B 205: 581 – 597
    (6) Of course, there are some good identification apps out there (e.g. Pl@ntNet for plants, Merlin for birds), but they are for hobbyists. Besides, who is going to produce the data required to train the artificial neural networks?
    (7) M.W. Browne (1988), The Debate Over Dinosaur Extinctions Takes an Unusually Rancorous Turn. The New York Times (19 Jan 1988): C1 + C4,
    (8) Currently there are 110 known invasive species in British Columbia alone. See: (Accessed: 7 Mar 2024).

    1. Charles Krebs Post author

      Michael – wise words, and I can find little to disagree about. Science is always changing but classical biology has suffered a big hit in neglecting the taxonomy classes of old. I am not sure how one could decide if biology is a poorer science than other sciences. Certainly bandwagons are plentiful in ecology, and many are simply technological and lead us into ignoring approaches that are not modern. Complexity eludes us and makes us forget the two signposts of good science – what is the problem? and what next? What can we do to focus and sharpen our understanding of the problems of the day, and what background data do we need to move in these directions. Biology and ecology in particular are the antithesis of what we might call “the iphone model” where change becomes more important than progress in understanding. So perhaps humility should be the guidepost for ecologists, and a sign of that is not to ignore the past. And admit that there was intelligent life on Earth before the year 2000. Thanks for your comments.

  4. Harry

    I agree with your view, especially as distilled in your response to Dr. Nummelin’s comment.

    I’ve independently noticed a tendency for Canada/BC to focus more on biodiversity conservation, and show less interest for conservation of at-risk species (a great inconvenience), and that makes me nervous. Focusing on biodiversity might be more convenient than focusing on species at risk. However, while protecting at-risk species and their habitats will conserve biodiversity, the opposite is not necessarily true. As such, I am nervous about this recent focus on biodiversity, whether its measurable or not. I believe my point aligns with what you’re saying.

    Thanks for ranting about this.


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